Honestly, I feel the exact opposite when a for profit company does that, because inevitably they ask themselves the question "how can I squeeze every last dollar out of this possible?", which is never, ever, good for the product.

Capitalist hyperfocus on short term quarter-over-quarter gains is toxic and destroys pretty much everything it touches, if not entirely then at least in quality. While I appreciate the amount of development those companies bring to the table, the moment they're in control of the project they'll try to find ways to profit from it at the expense of the community, and it almost always results in a poorer product.

Debian vs Mint for server, I'd agree with you, but for desktop, Mint is trying to do something Debian never really set their sights on: making it easy to use, particularly for people switching from Windows. Hell, they even have a version directly based on Debian instead of Ubuntu just in case something happens to make it so they can't run downstream of Ubuntu with a reasonable amount of work.

I think a better model for FLOSS in general is community owned and operated foundations that get backing from companies that benefit from those projects, but which do not let those companies gain sole or majority control.

*Just to stress, everything here is just my opinions and I don't pretend to have all the answers, just observations of the world and the impact for profit companies have had on it... For that, I pretty much never trust a for profit company to act in good faith for the benefit of anyone outside of themselves. They may do so for a time, but eventually most of them will become too focused on profit to behave as good citizens.