I know you’re asking earnestly, but the sad truth is the vast majority of startup founders care about the exit. Usually they also fail, unless it isn’t their main motivation, but the answer to your question is: most people who start companies.
Yeah in many cases it is "get something cool first and then leave it for somebody else to come up with a business model". Given the fleeting nature of success it makes sense to sell the first one and get enough to retire or be able to afford to lose.
