Without having read the article yet, here are what I see as the reasons people hate EA, and you don't have to look much farther than the 4chan or reddit gaming boards to see the evidence.
It depends on which angle you look at EA. EA Sports is disliked because of how franchises like Madden and NCAA Football were subpar products at the beginning of this current generation of consoles, and it's taken quite a few years to arguably get back to the standard where they were on PS2/Xbox. I completely understand the outrage here.
Then there's Origin. Steam and Valve are beloved by the PC gaming community, and when EA had to pull games from Steam because they wanted to handle DLC transactions through Origin, it pissed off a lot of those gamers. On top of that, there was an overblown cry about Origin being spyware based on their EULA and that it searched the hard drive for games to add to the Origin library upon setup. What people forget or ignore is the fact that other services like Steam have similar EULAs, and Steam's service was also bad when it first launched.
Day one DLC is the another monster, and to my knowledge there hasn't been many EA games with said DLC on the disc. Mass Effect 3 had some of the From Ashes assets because BioWare had to abandon it in order to make their deadline. Personally, I don't much care one way or the other about day one DLC as long as it's not entirely on the disc (*cough* Capcom *cough*), and while I would have liked to see BioWare push back the release date for ME3 so they could put out a more polished and complete game, I can see why EA had them push it out with a Fall 2012 lineup that looked like it was going to be packed.
There's also a dislike based on EA's acquisition and closing of studios like Bullfrog and Westwood.