The acting is horrendous. They find big, burly guys and try to teach them how to act. Sometimes it works (Rock, Stone Cold, Ric Flair, ect were all great), but mostly it's just unwatchable.
The in-ring product has changed a lot it seems, too. Less hard hitting, much more transparent. They rely on the camera work and strategic cuts to hide the mediocrity.
When you hear hardcore pro wrestling fans defend wrestling, they say things like "no, it's an art. It's story telling. Each match tells a unique story." It's nonsense, all pro wrestling matches fit into a certain formula. It's been done a million times.