Banks collapsed because they had crap IT. This is why Bear Stearns has a 20000% increase (yes, percent) in failed trades in the last two days of their life and didn't know about it. Bad IT also let them create these derivatives and have no idea how much risk was actually in them, hell, how much money was in them.
Startups are going to go through the same thing. They're lack of attention to detail of the total product quality while promoting their "full stack" as if it were high quality is already starting to bite them. I know a lot of these exits you're seeing would have been higher if they had better operations than they do.
So this myopic view that it's all about sales at any cost and "user experience" only does nothing for the industry.