[naasking]

It's not irrational. People often don't know what they want, or think they know but often devise overly elaborate solutions. Also, building before asking means you can potentially create a new market with a new product that's never been seen before, which is far more lucrative.

[curun1r]

Also, people are more able to communicate their wants and needs as deltas rather than absolutes. Creating something as a starting point is a great way to seed the conversation and get people thinking, even if that something doesn't end up getting used in the resulting product in any way.

[FiveSquared]

See YouTube

[starbugs]

AFAIK, YouTube started as a dating site and then pivoted based on actual usage patterns. See https://www.cnet.com/news/youtube-started-as-an-online-datin....

The whole thing wasn't built to become what it did. That's why you shouldn't build (too much) before starting to sell.