Wait, what?

I like "Buffy the Vampire Slayer," but I was a latecomer to the series, only really starting to watch it in the last several years. I really enjoy it, but I still haven't watched the last two and a half seasons or so. Now that I have both the complete sets of "Buffy" and "Angel," I figure I'll go back and watch both all the way through (with all the appropriate tie-in episodes and whatnot) at some point in the near future, but I haven't gotten around to it yet.

Avoiding the show as I did means I also avoided a great deal of Whedon fandom; my first real encounter with him was "Astonishing X-Men," and I'm pretty sure I watched the entirety of "Firefly" before I saw a single "Buffy" episode. So while I haven't exactly been entirely untainted by spoilers, I've been mostly untainted by prevailing fan opinions.

Which is why I was surprised by a throwaway line in a recent Blog@Newsarama post, referring to Riley as "the character’s most-loathed ex-boyfriend." I actually quite liked Riley, and generally enjoyed the whole Initiative storyline.

So now I'm curious: why is Riley the "most-loathed" of Buffy's boyfriends? Why does he provoke the wrath of Whedonite fandom so much that his getting a one-shot comic is cause for controversy?

And is there any chance that we could see Whedon's proposed TV series prequel about young Giles done as a comic? Has it already been done? Because that would be the thing that gets me buying Buffy comics.