Actually, that whole description should be scrapped (cause Mario and Donkey Kong were trying to kill each other in their first appearance) and replaced by something like "Mario's first nemesis, and the titular character of Mario's first video game" or something like that.
Just about every? More like a few. We have had 51 featured articles, two of which have been unfeatured while seven are currently being deliberated. It's hardly "just about every."
And sometimes articles simply don't maintain the same level of quality, especially for subjects that appear in...
It's probably because we have a lot of four-year old users. :P
Well, that might be bit of an exaggeration, although I've been playing video games since I was about six...and my brother has been since he was about three.
We are not going to be merging short articles. What we are going to do is try to have all new articles reach a minimum standard, so we don't have hundreds of one or two sentence articles all over the wiki.