Alright, that I can work with. It seems to me that the main problem here is simply a manner of semantics. It's true that by it's broadest and original definition in the english language, the word meme fits in with your idea. An Internet Meme, however, is much more narrow in what it refers to, generally being an idea or concept that is propagated within the internet itself.
Internet memes are typically something that hasn't been seen before, that catches people's attention due to how much of an emotional response they get from it (awwing at lolcats, laughing at rage comics, screaming at Friday). It might not even be something they themselves get an emotional reaction from, but they see others reacting, and decide to copy whatever elicited said response, with their own twist. Then it propagates from there. It's basically a matter of monkey see, monkey do, with a bit of telephone thrown in.
The term internet meme was originally used for these kinds of things, but, due to many people not being aware of the word meme outside of them, the term got shortened, and meme itself took on a new meaning, because that's how slanguage works.
KYM has always been specifically about internet memes, but came about when the term "meme" was already referring to the internet variety as it's main usage. That the site became popular only helped to solidify that.
Dropping the phone on one's face isn't a concept that people will want to emulate, nor will they be likely to see a comic about it, and then want to emulate that. As you said on the page, mutations wouldn't really add any value to the original concept. Sure, people will agree with the concept, but they wouldn't be likely to take the comic and post it elsewhere. The idea itself isn't one that's likely to spread virally, and as such, isn't really worthy of being call an internet meme.
Leastways that's my opinion on the matter.