I maintain the biggest problem has little to do with the content, but more to do with the presentation. The attitude era didn't succeed because of ultra violence or blood or puppies or whatever. It succeeded because they told several stories at at time, and didn't rely on the same characters telling the same stories over and over. They also took a good amount of characters seriously, and had many contenders, any of of which could beat anyone else at any given time.
Right now, they pretty much treat Cena, Lesnar, and maybe Taker and HHH as serious characters, and everyone else is somewhat interchangeable. Hell, Seth Rollins has been the champion for roughly 5 months, and isn't even taken seriously.
I think a big problem is that they tend to market to stupid children. What I mean by that, is that they market to kids, but assume kids are complete idiots who can't handle anything other than the status quo, or can't follow a story with multiple characters, which is really pretty insulting. I don't have kids myself, but I have nieces and nephews, and a lot of the kids shows they watch are FAR more complex than seemingly any story WWE cares to tell.
Another major problem is the extremely awful 50-50 booking. It seems like they think it makes everyone look equally strong, when in reality it makes everyone look equally bland. I mean, what is the point in getting invested in any feud, if its just gonna be like that? That's part of the reason I think this Lesnar-Taker feud is lame, besides being a sequel to a bad match, the Mania match was one of the few matches that had real consequence, and having another match(especially if Taker wins) basically negates that first one mattering, but more than likely Taker will win and they will have a third match at Mania again. Which in theory sells tickets, but what would really sell tickets is if they had enough people to matter, that they didn't have to dig up these barely mobile vets every year. Which is 100% the fault of bad/lazy storytelling.
Similarly the Cena US title run has been great, and has had a lot of quality matches and built up a lot of goodwill for Cena, and whoever finally beats him should, in theory, become a legit main event talent. If however, Cena beats Rollins for the WWE title, then this was all a stupid, pointless waste of time. It just becomes another nobody matters but Cena story, and all the raising the profile of the US title stuff gets flushed down the toilet. If Rollins wins, it becomes the big win he's needed to legitimize himself as a main event guy, and maybe become the 3rd guy who matters in the company.