Kel was funnier but that physical comedy doesn't age well as you get older.
Kenan was more of a straight man which is more universal and can be played at any age.
You are spot on pointing out the different styles of comedy each performed, and voters will take sides based on the type of comedy they prefer. I wouldn't go so far as to say physical comedy doesn't age well though. Watch a 25 year old episode of Seinfeld, and Kramer is still the scene stealer. Even for someone like Bill Cosby, his most memorable stand up jokes are when he acts them out. Also when you see lists of top comedic actors of all time, its chock full of physical comedians (Robin Williams, Charlie Chaplin, John Belushi, Jim Carrey, Steve Martin, etc). Everyone has their preference though.