Because EA's philosophy used to be what Activison's is right now. EA now takes the stance of "we need to make our games good." and we've seen them introduce new IPs that are of a good quality.
What I think is hilarious about their press release about killing Guitar Hero and DJ Hero is that they've said that they're shifting their attention to CoD. There are now....I believe over 4 development teams working on CoD. The ashes of Infinity Ward, Treyarch, Sledgehammer, Raven (presumably) as well as another. And you know what, I'm happy that Guitar Hero is dead. I'll also be ecstatic in 3 years when people are sick of Call of Duty and that dies too.
I used to boycott Activision products because I really, really hate what they're doing to the industry. It's been really easy because Activision hasn't released anything that I'm even mildly interested in.