Hmmm, well my thoughts to this are:
#1: I guess this means "Fun Space Game: The Game" is dead? Sad because I thought your (Yahtzee's) space adventure game "Galaxy Of Fantabulous Wonderment" or whatever it was called was quite fun and amusing when I played it all those years ago. Ironically it's because of THAT game (and a few other freeware works) that I ever wound up following Youtube reviews and eventually this video series.
I guess I should be sadly humming a dirge here.
#2: I wonder how long it will be before Poacher "rule 34" appears. I've always kind of thought that the trend towards unusually gorgeous female characters in video gaming might be an attempt to mitigate the "creepy factor" when fanboys start working for it. I suspect the eventual results (as obscure as they might be) to the protaganist of poacher will be... disturbing, given that same sort of fugly working man vibe.
I'll leave it to your imagination if I'm serious about this, and use this logic to rationalize gaming trends, this however brings me to something more frightening:
#3: Yahtzee, you've been around the neighborhood of the Internet for long enough where you have doubtlessly heard of this group of people called "furries". Those who are obsessed with and typically sexualize anthromorphic animals to the exclusion of other interests, going so far as to dress up in fursuits to have sex with each other and so on. It's actually more sizable than you might imagine, and has quite a solid prescence on the internet and throughout the connected genres of fandom. This subculture keeps many things alive including entire catalogs of pornographic (and non-pornographic) comic books, and various old TV series like "Ducktales", "The Mighty Ducks", "Chip and Dales Rescue Rangers", and others.
Sometime the brave who are unaware might want to head out and do a search for sonic porno, and suddenly the increasing cast of characters involved in his storylines make a degree of sense. You'll notice there is one that seems almost optimized for any fetish you can think of.
The point is that I think Sonic survives largely due to the furries, who to be honest are grateful for any attention and products they get as many subcultures are, and to whom quality matteres less. Some of the more esoteric Sonic games represent a sort of wish fulfullment fantasy accross genres sort of like people's fanfictions come to life. Putting Sonic in gothic horror, or the middle ages to fight The Black Knight, or whatever is exactly the kind of thing this subculture does in fanfiction, or with their own creations involving their own characters.
I know a lot of people won't care for this point, but I think the furry interest and influance is greatly underestimated. I think for a long time Sonic has been being supported by this group, and it's actually only recently that we've seen games directed at the mainstream fans, rather than a niche group which overlaps heavily.
If your wondering who buys it, well again, look at all the energy put into it by the furries and then ask yourself if people that obsessed, who oddly even take their entire sexual identity from such things in many cases, aren't going to buy and support these games?