Master Crimzon
Baby Killer
DigiMark; Kingpin isn't a 'brawn'-based character. Why are you so unhappy if he degenerates in skill? It's not like that's his defining character trait.
Hell, even with characters like Magneto, who is a smart, complex villain, his mastery of magnetism is a defining character trait. If Batman suddenly got suckier in martial arts, it will piss me off. If Spidey was slower, it would be annoying. If Wolverine's healing factor was weaker, it would... make me happy. I hate that cheap healing factor.
Kingpin, though, is a smart crime boss. Just like I couldn't care less if Carmine Falcone could handle Batman in H2H, Kingpin isn't defined by his skill in fighting. He's more of a Lex Luthor type character than anything.
As you see, I have problems when characters defeat or hold their own against other characters which they would logically have no chance defeating. While I hate the using of PIS to make character feats redunant, these feats- while I suppose that they have to be accepted- are ridiculous. I mean, REALLY. Kingpin isn't even one of the world's greatest martial artist; he's not Batman, Deathstroke, or Lady Shiva. How the hell can he fend off Spider-Man, who is not only faster and more agile, but physically stronger as well?
That's, ultimately, why Modern KP > 'Classic' KP.