He is? I sure don't see it. I see a tiny few people who don't know how to stop yelling, but I don't see a giant mass of people or anything. XD
Don't really see any appeal in him, either.
I'm no fan of the Punch Out series, I couldn't even stand the spin-off in Abobo's Big Adventure. I just honestly believe that (for reasons previously stated) the stage is his.
I also think that Mac is one of two character types that are missing in Smash, the other being someone like Raiden.
Sure, he may look like he only does one thing, but Sakurai could implement an Excite-a-Bike guy, save for the jumping. There are plenty of things he can do, and he would have more of an traditional 2D fighter feel than the others. I wouldn't main him, but he would make Smash feel more complete for me.
If he looks slightly less brachycephalic than he did in Brawl, I would prefer that. But if he is implemented as a character, I'd be most worried that Sakurai would make him look like his NES version, which is far too ugly.
Speaking of ABA, does anyone here think that Abobo (how he originally looked, big, bald and orange-ish) should be in Smash?