The only reason I've ever been able to come up with, other than that they look funny, is that you're complicating the amount of "stuff" you have to assemble for a dive. I have to confess I have, on occasion, shown up at a dive site without my X-shorts, and therefore without pockets, and therefore unable to carry safety gear in the usual streamlined and accessible fashion.
Since I got through Cave 1 without anyone making a single comment about the X-shorts (in contrast to my Chuck Taylors, which were a running joke through the entire class) I don't think they're a deal-breaker.
Since I got through Cave 1 without anyone making a single comment about the X-shorts (in contrast to my Chuck Taylors, which were a running joke through the entire class) I don't think they're a deal-breaker.