I think Rogue Legacy is called a "roguelike RPG". *shudder*
I have to say that Chris' arguments were very convincing for me. I'm actually put off by many of these 'purist' discussions about some word or another, because, really, it's basically complaining about 'you do not use this word the same way I do', which I find narrowminded. It's the same way with every word: It has characteristics that it shares with similar words, its synonyms. It cannot be totally expressed by only combining any of its synonyms in any short way, it always has connotations that its synonyms lack. That's when you know that word is legitimately part of our vocabulary: It's needed to fill a hole in the web of meanings and connotations the other words of our vocabulary already form, the web being spanned by meanings and connotations shared by multiple words (yeah, I'm not very good at metaphors in English, but I hope you get my point).
For me at least roguelike means an at least partly randomized world with the implication of 'positional combat', whether it be turn-based or - like in Rogue Legacy - by quickly reaching the right distance to your enemy at the right time. It also implies managing some sort of resource, possibly one like hitpoints that you can deplete either very fast with bad play or very slowly with near-perfect play. Permadeath depends on the overall balance of the game and its length. I would consider a game with really cheap deaths (I-wanna-be-the-guy-style of cheap) to be very rude to also throw permadeath in your face, while a shorter or an easier game that e.g. focuses on good long-term planning and your ability to survive with the choices you made and the things you sacrificed to gain some other advantage would really lack its main gameplay element if it didn't threaten permadeath.
