In the public eye, the entire Donkey Kong franchise dropped off the face of the earth between DK64 and DKCR for all intents and purposes. There's a reason some DK fans label it the "decade of nothing," not the least of which is that, out of its eleven games released between 2001-2009, only two (DKC GBA and Diddy Kong Racing DS) cracked a million sales, and only barely (source, DK Vine). Some, like Barrel Blast, flopped miserably.
Still, the series' comfortable spot as Nintendo's fourth-best seller (fifth behind Wii paraphernalia) is a testament to DKC's popularity in the 90s. As such, though many players may not have beaten the games and seen K. Rool, the number of people who have may be proportionally close to or greater than those familiar with Ridley, based on series sales alone.
Then, of course, the Smash series comes along and laughs heartily at my little counterpoint. But that's a different debate.