It is can’t because this is how the door gets pushed open to making more and more paid versions of the operating system.

This invites more capitalistic practices into the “market”, and is what starts the downward trend.

I’m ok with selling software. But selling the OS at all just seems like a big step that should never be taken.

Selling a paid upgrade is kind of a gray area, but it should be an extra piece that gets installed separately, cross-compatible where possible, and shouldn’t affect your ability to upgrade versions for damn sure. I’ve never dealt with it directly, but if it’s like you said and you need to do a complete reinstall to upgrade versions but downgrade from pro to regular, then you’ve already detected the first tumor.

Yeah the entire existence of any “pro” version of anything is cancer.