When you know something can be changed relatively easily, say compared to a building or a car, the tendency is to do it. Especially when there is no tight feedback loop telling you what is a right and wrong move. The churn is the result of the psychology of uncertainty combined with the ability to act on that anxiety.
Shipping MVPs or minimal features quickly and seeing if they stick is a solution. Quick and dirty until you know something is worth further effort. Yes, user feedback is good but often people don’t know what they want, or think they want things they won’t actually use, and you won’t find out until it’s sitting in front of them.
And someone is always yelling that everything is taking too long, usually the same person who told their boss that something would be done by x date without asking anyone else.