I rarely get involved in deletion debates these days. The problem is the whole concept of "notability" is definitely screwed up. Notability on Wikipedia is supposed to be objectively decided, but that runs contrary to establishing notability in the first place. To some an article on a certain topic might be important, but other people it might be something that should be deleted.
Normally this is where editorial supervision would come into play. For better or for worse, this is how it works in professional publications. People higher up decide what gets put into the book, what makes the newspaper. But there's no editorial hierarchy on Wikipedia, so that's out. So we're forced to adhere to some vague notion of notability, which basically states that anything that's mentioned a few times on the Internet is notable, nevermind old topics that might only have print sources that may or may not exist.
But by maintaining Wikipedia's facade of "The encyclopedia that anyone can edit", they've refused to do things that would be the first steps in any large professional writing project. That is, relying on a set of topic experts, quality copyeditors, fact checkers and researchers and professional level editorial staff that decides what's in and what's out. Citizendium has tried to establish such a system, but as they're finding out it's hard to get quality editors to do this stuff for free. It's far easier to do what Wikipedia does and let anyone whose passions outweigh their expertise and ability to contribute on a short leash.
The result? An encyclopedia that's quite imbalanced. E.g. we get tons of people weighing in on the debate for the notability of an Internet games review site, and far less people working on stuff like Mathematics and Health-related topics, stuff people get paid top dollar for their expertise on, but wouldn't necessarily write about for their own leisure. If you look at the
featured articles, you'll see that there's lots of articles on pop culture stuff, recreation and warfare (stuff people like to write about for fun), but far less on seemingly cornerstone topics like Education, Math, Healthcare and Chemistry.