There are a lot of genuine serious issues. Not that I'm all that into the culture, but I can see the lack of games that appeal to a certain serious hardcore has parallels with other media. Literature fans want deep challenging philosophical concepts, but find the shelves filled with airport thrillers.
Depression Quest is terrible. Wordy and highly preachy with a tedious storyline. Even for a morality semi-interactive story, there are better examples of the genre which have things like plot, and snappy dialogue. No idea why it got the publicity. I think GG may be seeing this as a reward for sex, but it's really just that the journalists and piblishers go to the same parties and the publishers have the ear of the journalists. It's pretty clear that a lot of publishers are very willing to do a lot of hobnobbing with the journalists, and giving some quite expensive gifts. Hell, Ubisoft was giving out Nexus tablets. They exactly weren't doing this out of the kindness of their hearts.
A good chunk of gamergate is made up of teenage kids though, and adults that behave like teenage kids, who really aren't very good at people skills. It's a large part of the gamer demographic. The fixation on certain people within anti-GG really causes the movement problems. Anti-GG is made up largely of very self-righteous professional victims who believe they are always in the right, and know how to spin chlidish abuse to their own ends and manipulate the media into thinking that the same people haven't been turning a blind eye towards doxxing and threats themselves for years.
The other part of it is that the internet itself can be vile! Factions form, and the dogpiling starts. Nobody is actually in control of the online mob and the worst perpetrators of both sides and up being seen as representative as of the whole.