So did Hulk Hogan, also a horrible actor. Wrestling and acting are very different things imo, also often different audiences and expectations. Plus having screen presence is a bit different than working a wrestling ring, I haven't seen many wrestlers that have made the transition well. Rock's had the best career in movies I'm sure, but I actually enjoyed Roddy Piper in They Live a lot more than any Rock performance, even though Piper's probably a worse actor (technically).
Really I don't really remember Rock doing much as a wrestler other than the eyebrow thing and "can you smell what the Rock was cookin". Mostly just shouting catch phrases and possessing a good physical presence. Piper and Macho Man by comparison seemed a lot more colorful for instance, but to each their own.