It all depends on your coaches and you. Here is my history:
- Never was very athletic through college. I swam a lot in highschool and was in reasonable shape, but nothing phenomenal. Ended up gaining a lot of weight through college.
- Started crossfit about a year after graduating college and went to a gym that a friend of mine worked at. I only went because it was free. The coach there had no on-boarding program and while being certified, was clearly not a crossfit coach. He didn't do his own programming - mostly borrowed standard programming from crossfit.com and implemented some non-crossfit programming. Anyways, because I had no idea what I was doing, and he didn't coach at all, I badly hurt myself doing deadlifts (or something similar) and struggled for a couple of months with a significant amount of low back pain.
- The second crossfit gym I went to, after I moved to northern california, had a good on-board class and the coaches were extremely well trained in the movements and took a lot of time to ensure perfect form. I started going nearly every day and gained a significant amount of strength. I went from being afraid of deadlifting 135# to 265# in about a year.
- After moving back to southern california, I started going to my third gym. I've been there almost exactly a year now and my deadlift is up to 375#, my squat is up to 345#, snatch to 165#, and I do nearly every workout RX and have started competition classes. The coaches here give great cues and outside of normal soreness have never been injured or strained more than a good foam roller and lacrosse ball can get out.
I'd say everyone's perception and experience is different, but if you injure yourself crossfitting, then you're a) at the wrong gym or b) pushing yourself too hard and not listening to your coaches or your body.