Share and share alike. That's it.
His goal is freedom zero, the freedom of a user to use the software as they want.
RMS doesn't, but others also in the copyleft camp certainly have. E.g. https://sfconservancy.org/blog/2020/jan/06/copyleft-equality...
For people who believe in this, please study your history — look up the claims and counter claims around Emacs, specifically how it was created, commercialised, and then liberated (then forked and merged again).
“Good intenshuns” (my somewhat humorous term for “spirit”) is no way to settle even moderately complex commercial disputes — say for a text editor which in those early days of late 70s/early 80s, had very niche appeal and a small user base.
In the 21st century, with bigger markets and more money at stake, “good intenshuns” matters even less and this is why we have a bevy of F/OSS licenses to suit every need.
It’s very telling that RMS needed to create a license to support his vision of Free software. Perhaps from his experience he realised that legal code was the best way to enforce desired behaviour.