Everyone seems to think so. I’m on the fence at the moment, though I must say it isn’t the worst anime of the season, and probably is about average. There are far worse shows, such as Ghost 07 where pretty boys love each other really hard, and Tayutama, a really bad version of Inari-sama.
The main reasons people don’t like Shangri-La can be broadly categorised into two main types. The first is, an unfulfilled potential that arose from overly high expectations created by impatient youngsters. Gone are the days when anime series can take some time to do a bit of exposition and slowly become awesome. These days, impatience and instant gratification are the norm, and any first episode that is not automatically awesome leads the anime series to be classfied as "fail". This leads to the primacy effect, where first impressions are given far more weightage than subsequent knowledge. Such changes in consumer taste has the dire effect of making anime companies blow budgets on first episodes, then heighten expectations, and subsequently fail to achieve them.
The other reason is confirmation bias, where people basically just seek to confirm what they already think, without considering other alternatives. People think GONZO sucks, and thus watch Shangri-La to spot instances where GONZO sucks. If you read other anime blogs which flame Shangri-La, you’ll notice such observations like "incoherent plot", "boring", "carbon trading is not exciting" etc. It’s pretty obvious that the story hasn’t even kicked in yet, but no, it’s "incoherent" already. It’s a self-fulfilling prophecy, where people think GONZO sucks and then make themselves believe that Shangri-La sucks.
Now I’m not saying it doesn’t suck, there are certainly issues with it. For one, the voice casting of Ayu from Honey and Clover as Kuniko is fucking terrible. I have this strong urge to rape and kill her brutally with candles everytime she speaks, especially if she goes on her "ne ne ne" hyper combo finish. The exploding tanks in the OP are another small issue, which people mock the show for, but in truth, exploding tanks have yet to appear in this show! The animation is not that good, that’s for sure, but only if you compare it to the likes of Bones’ or Sunrise’s. Compared to even A1 studios’ Birdy, it’s like godly already. But that doesn’t make Birdy a bad show. Anyone who can’t see past animation quality is a shallow Zaitcev (the Russian word for hidden ninja blogger).
The good points are far more plentiful. We have a polarising resistance group who basically rob the government. It’s nice of them to show that such acts have repercussions, since many of the public don’t actually like them. Kuniko’s the Princess of the resistance, but she’s an idiot. There is not moe fanservice in this show and no panty shots at all, which is as awesome as telling your retarded little brother not to drool and he actually follows the command, since GONZO is all about the panty shots. We also have an interesting carbon trading concept, which is run by a shadowy group of child prodigies of something. I assume these are unaffliated to any organisation, and essentially sets up a 3-way power struggle between the neo-world of Altas, the resistance and the profiteers.
The funny thing is, after writing this post, I actually like Shangri-La more than before. This is due to cognitive dissonance, where attitudes and behaviour collide and humans find some way to justify their behaviour to reduce this uncomfortable state of dissonance.
Savvy individuals will be able to spot that I have a psychology examination coming up in a couple of days, which explains the liberal use of the lingo in this post.