Before I begin, I just want to say that I'm not trying to cause trouble, and I hope that replies to this post (if any) won't simply be declarations in favor of one side of this issue.
The issue seems to have begun with a curious confusion of mixology with glassware. For some people (even people who understand the difference, as a recent post makes clear), a cocktail glass is **really** a martini glass. It's not hard to see how that came to be, given the ubiquity of the martini as the drink of fashionable trendsetters from Nick Charles to James Bond. Most people who've seen these movies would never buy glasses made especially for drinking cocktails, so what else would they call that funny-looking glass?
This raises a not-so-interesting question for me: does the difference matter? The answer is, obviously, only to some people; which raises an interesting question: what's the difference between the people for whom it matters, and those for whom it doesn't? If you you've never heard that the glass that a martini is traditionally served in has a name of its own, then clearly you aren't qualified to speak to the issue; but if you're aware of the distinction, what determines whether you choose to recognize it?
I don't see any need to get upset about this--Nick Charles would no doubt have sniffed at the idea of a "vodka martini," but I can't see him getting worked up about it. It just makes me wonder, and I wonder what other people think.