Honestly the reason you see guys like this on stage is down to what i think are a few different things. Namely-
Insulin usage too early and too much.
Shit diet.
Shit gear
Shit genetics
Laziness to seek out good gear, train hard and correctly, and diet properly.
but the biggest one i think is that these guys are so insecure. They get tons of compliments from people at the gym and outside the gym for being so big and looking good with a shirt on, that they actually think they look good enough to step onstage and compete. They diet and drug and invest moeny and time into it, and then they realize they look like shit but already shelled out the cash for the show and decide why not ill give it a try anyway maybe i can come in the middle somewhere. The delusion factor plays into this as well, as they probably have an instagram or facebook where they put up progress pics and get tons of compliments from people. I'm sure that guy looks good in a t shirt or a loose tank top at the gym, but the midsection ruins him totally.