I was under the impression it has been sports entertainment for a long time so they weren't held to the same regulatory standards as proper sports.
However would agree he is very stubborn and will want to prove himself.
Vince in an interview once said something along the lines of "wouldn't it be great if we could get that wrestling word out of wwf". You can see him say that and gibber on in the video above from the 14:52 mark.
That's just how he thinks, his product is no different from any other wrestling promotion, the main difference being far better production values. He honestly thinks swapping out 2 words makes what he does different from everyone else. Its no different to when one day suddenly wwf fans were referred to as the "wwe universe", that came out of nowhere and people were like "wtf is this", the commentators prattled on for weeks like it was something the viewers had always been called.