This happens in non-solo founder companies too. In fact, I would expect it to happen slightly more often in companies with multiple founders, because they jocke

This happens in non-solo founder companies too. In fact, I would expect it to happen slightly more often in companies with multiple founders, because they jockey over what the roadmap should be. When there's a lack of leadership at the company it's a big problem, but it happens at all types of companies, not just small solo founder startups. I think you are conflating the problem with the fact that there is only one founder.