They shouldn't be. If someone has chronic tendon or joint issues, that's something to discuss with a doctor and a trainer.
I am a super introvert and know at least half a dozen folks with such issues, more if you include my close friend group.
Any place that has a lot of physically active people stressing their limits a bit is going to have a lot of injured folks over a decent period of time. And of course it gets talked about quite a lot, since it limits performance and ability.
My trainer knows I have a chronic shoulder issue, and an adductor issue at the moment I'm working through that we need to avoid stressing too much. The few other folks who tend to work out around my schedule know of this, and I know of theirs.
Not very uncommon really.