Older Than They Think: The producers claim to be the first major animation project with an openly trans woman voicing a regular character. Not only is "major" debatable, but fans of Maddie Blaustein were very angry to see her erased for marketing points.
Snark Bait: The reason it's worth checking out at all because the show tries so hard to be diverse as to be token and it's clear that being "progressive" is their main selling point. And, much like The Emoji Movie, its embraces the worst stereotypes about its subject matter and audience and markets them to its subject matter thinking they are entirely true without any hint of self awareness.
Uncertain Audience: According to comments on the promo, many (jokingly) assume that the creators were probably aiming for the Tumblr crowd, who are most likely young adults. Judging by the tags under the show's name, many people there don't like it either. Either way, it can't decide whether to appeal to that crowd or sitcom fans, hence the confusion and backlash.
Unintentionally Unsympathetic: Shona's rant about Twitter names, jobs, and diet soda at the beginning made her sound like a disillusioned kid who has no real world problems which shows the worst stereotypes of Millennials who spend their time on Tumblr right off the bat. Was there any wonder why so many people jumped down on this show's throat before it was even released?