Connor wasn't a real boxer. Mayweather toyed with him
Your second point is retarded MMA fighters are bad at everything until they put it all together and even then they still ain't the best. They wouldn't have made it far in pure fighting rules of BJJ, Boxing, Muay Thai, K-1, Lethwei, etc. If Connor stuck to the boxing world he wouldn't be known today.
You probably going to a MMA gym now which is why you defense this so hard

Your hands will never be good as a boxer's, your kicks will never be good as a Muay Thai expert, your grappling will never be as good as BJJ expert.