Personally, I think the problem lies half with the balance and half with the community. A big part of the community wants to carry/be a nig guy, and support is the only role that doesn't really convey that feeling (in most cases).
Personally, I believe that out of the current standard roster of supports, all of them are either pretty bad (Taric/Zilean/Janna), really not enjoyable to play (Soraka/Nami) or eveyone is burnt out of seeing them (Thresh/Leona/Braum). People are so despaired about the current roster that I've had a roughly 15-20s queue time average on support shaco for like 10 games. I'm seeing more Gangplank/Shaco/Poppy/Brand/Veigar/Volibear than I'm seeing Lux/Galio/Zilean/Janna/Soraka/Sona. It seems that right now, the standard definition of support is "can kill the enemy ADC and/or proc spellthief/targon efficiently".
However, that's not 100% on Riot's fault. I think that the main gripe with support is "giving kills". Personally, as a Poppy/Veigar support main, every single kill that's within my reach, I will take. And I personally feel that on every single supports, taking a few kills is better than a 8/0/0 ADC. Since the kill-assist gold is usually about 150gold (225g if you're 3 guys taking the kill), I believe that letting it to the lowest income character will influence the lane much harder than leaving it to the cash-stacking one.
If people were less mindful about supports being ideally 0/0/77, I believe that there would be more support players. And for people finding it farfetched, it's a pretty common thing in DotA to try to get those early kills on your support, so there may be a reasoning behind it (although the reasoning is exacerbated in DotA's case because of the nature of the game).