I'm indifferent to whether it get split or not, but I would strongly
like to stamp out the names 'Mario Type' and 'Kirby Type' completely; they're totally non-indicative and, depending on which games from their series you've played and your own personal experiences, potentially actively misleading.
Both series are extreme long-runners who have had installments with easy levels and hard bosses, and installments with hard bosses and easy levels, as well as various combinations of the two. In particular, as the page notes, there are plenty of Mario games where the bosses are as hard as the levels or harder.
And in Kirby games, it often depends on what power you bring with you — most bosses can be a cinch with the right one.
Remember that this trope is at least somewhat subjective — some people will find a level easy and struggle with the boss; other people will find the same level difficult but breeze right through the boss at the end. Even using individual games as names for the types would be potentially problematic; using two series that have both constantly reinvented themselves and changed radically in difficulty level throughout their lifespan is silly.
(And, again, Kirby is a particularly terrible one to use for the namer, since most of the time, its boss difficulty depends on what you bring into the fight.)
edited 11th Oct '11 1:08:31 AM by Aquillion