Matt and Trey above all else are Anti-Establishment, Anti-Authority and Anti-capitalist/corporatism, but especially the former two to a fault. They do both sides a whole lot of stuff, but they also make pretty hard-line stances against a lot too, especially anyone trying to tell or force others to be or act a certain way. Unfortunately that is something they do to a fault at times too.
Their biggest issue in my mind is that they've failed to separate the moralist liberals of their formative years with liberals of today and the issues today that are at the forefront. Sure there's no shortage of terrible people tumblr and some other social media but in terms of actual politicians and major social movements it's not like it was in the late 80s and early 90s with people like Tipper Gore, Joel Lieberman and even Bill and Hillary Clinton trying to censor media to "protect" children. We still have tons of shitty politicians on both sides, but it's simply not the same as it was years ago. They're shitty for a lot of the same reasons, but the issues and policies have shifted so much.
The polarization of the Left and Right, Democrats and Republicans, is something so extreme that you really cannot both sides many of the important issues going on like you could back in the day when there was a great deal more overlap in many areas.
I think they tried to be more pointed with last season why retaining their signature humor, but it just didn't translate as effectively as they may have thought it would. There has been some hints they've learned from it and I hope they have. But we'll know for sure Wednesday.