Back in the day, nullsec was much less accessible for carebears than it has been in the last few years. More for cultural reasons than anything else, but CCP has also altered the game mechanics to encourage alliances to more actively farm their sovereign space too.
People who did low risk carebearing or “krabbing” or whatever you want to call it, as a primary playstyle, they just did it in other places. For the most part. Most notably in highsec. The game survived, even thrived, and nobody was “prevented from playing”.
I can sympathize with the frustration when CCP nerfs your playstyle in some way that makes it no longer seem viable. I used to be a ninja salvager, then spend most of my EVE career as a solo or small corporation wardeccer. These playstyles are effectively nonexistant today. It sucks, but I found other stuff to do. EVE is good like that - lots of gameplay options.
These changes don’t prevent anyone from playing. They just make you find a different way to play. If you don’t want to adapt, I understand that too. No need to play a game that you don’t like - safe journey wherever you go from here.
Face it though, EVE is a constantly changing game. Any particular playstyle is eventually going to disappear. Its your choice whether you want to adapt or not. Probably all long term players have had to make that same choice from time to time.