This won't work

Why people instinctively look for flaws in new ideas, and how to interpret that feedback

Have you ever noticed this pattern?

You show something you’ve come up with, like a mockup, a half-built feature, a rough prototype, and before you’ve finished your sentence, someone is already finding the hole in it.

“Yeah, but…”
“What about the case when…?”
“Why didn’t you put…?”

Like a reflex. It’s not even wrong half the time. But it lands like a punch to a bruise.

And if you’ve spent any time building products, you’ve felt the frustration: you’re trying to explore possibility, and the room immediately collapses into critique.

What makes this strange is that it’s the opposite dynamic from the one Rob Fitzpatrick describes in The Mom Test, where the goal is to avoid false positives and force people to reveal truth through skepticism when you share a potential idea. Because by default your friends say “yeah, that’s a great idea” when they mean nothing. Likewise, user interviews can easily skew toward false positives because people are conflict-averse.

But when you show what you’ve actually built, your very first MVP maybe, the room goes forensic. The feedback is too critical, too early, aimed at the wrong question.

Both are failures of calibration. And interestingly, both have the same root:

People respond less to the actual idea, and more to the social and psychological incentives surrounding it.

To be clear, I’m a big believer in validating ideas early by getting real reactions as soon as possible and killing weak ones fast before over-investing in them. Most of what I write about product comes from exactly that mindset. This is not an argument against criticism. It’s about learning to distinguish between feedback that helps validate or invalidate an idea, and feedback that comes from instinctive defensiveness toward anything new.

Our brains are wired to protect

The first explanation is evolutionary, and it’s real even if it’s overused.

Human cognition is dramatically better at spotting what’s wrong than imagining what could be right.

From an evolutionary standpoint, that makes a lot of sense. Missing a flaw could be dangerous. Missing an opportunity? Less so.

The brain is a prediction machine. It runs constant pattern matching against what it’s seen before, flagging deviations. When you show someone a new product idea, their brain doesn’t ask “what could this become?” It asks “where does this break from what I already know works?”.

But the thing is, most of the time, early ideas are, almost by definition, full of deviations from known things. That’s what makes them interesting. But the brain’s risk detector reads “interesting” as “threat”, and if you judge them purely through a risk lens, everything looks broken.

When someone looks at your prototype and says “this won’t work”, usually they’re not evaluating your product’s potential. They’re evaluating it against some implicit reference. Usually a finished product at scale. Maybe with full-time engineers and years of iteration behind it.

The social cost of optimism

There’s a second mechanism running alongside the cognitive one. Being critical is socially safe, and being enthusiastic is not, and I know it sounds counterintuitive. Let me explain.

When you point out what’s broken, you’re protected. If the idea fails, you saw it coming. If it succeeds, you were just being rigorous. There’s no bad outcome.

Pointing out flaws signals intelligence. It shows sharpness, experience, taste.

Besides, supporting an idea, especially an early one, feels riskier, and it might make you look naive if it fails.

When you support something early, when you say “this is actually interesting, here’s why it might work”, you’re exposed. You’ve attached yourself to something unproven.

Which is why random feedback, even with the best intentions, tends to drift toward autopsy mode.

There’s a version where the critic is right

Sometimes it’s you, the builder, who is wrong.

Sometimes the edge case someone raises isn’t premature, it’s actually the core problem.

The early-stage builder is just as capable of distortion as the early-stage critic, just in the opposite direction. Founders are famously prone to over-investment in their own ideas.

The same emotional attachment that keeps you going through hard periods can blind you to signals that something is broken at the root.

“Rule of thumb: You should be terrified of at least one of the questions you’re asking in every conversation.”

― Rob Fitzpatrick, The Mom Test: How to talk to customers & learn if your business is a good idea when everyone is lying to you

Criticism is not bad at all. It’s that most feedback conversations have no protocol, no shared understanding of what mode they’re operating in. No alignment on whether this is an exploration or an evaluation.

Two modes of feedback

There are two fundamentally different things you might need from feedback, and they require completely opposite postures.

The first is oxygen. Early-stage oxygen means:

What’s interesting here?

What could this become?

If this did work, why would it matter?

It helps you see what you’re actually building before you fully know.

The second is pressure testing. This is where “criticism” belongs, but it’s a later-stage question. Once you know what you’re building, you need someone to hit it hard. What breaks? What’s missing? What have you assumed that might not be true?

Expecting people to know which one you need and when is a stretch. It’s on us, product people, to know what we’re trying to validate, and ask accordingly.

Most of the time, you go into a feedback conversation and just say “what do you think?” which is about as useful as asking someone if an outfit works without telling them whether it’s for a wedding, the office, or a night out. The person in front of you has to guess what kind of response would actually help, and they’re running on social defaults.

One of the most underrated skills in product comes in here: knowing exactly what question you’re trying to answer in this moment, and naming it explicitly before asking anyone else to engage with it.

It’s okay to protect the “spark” until it becomes a flame, but we cannot outdo ourselves by being in friendlier rooms only. We can do it by being precise about what we need at each stage, and stopping outsourcing that judgment to whoever happens to be in the room.

If you’re reading this as a builder:

The instinct to protect your idea from premature criticism is correct. But your job is to sequence the feedback, not avoid it. Name the mode you’re in before you show anyone anything.

If you’re reading this as a feedback-giver:

Notice the reflex. The first thing your brain produces when it sees a new idea is almost never the most useful thing you have to offer.