When I lived in Texas I was active with Open The Taps, a grassroots organization that sought to be a voice for consumers to change beer laws. What I witnessed during that involvement was a lot of nasty tactics from AB keeping beer laws terrible. Sometimes via their distributor partners, sometimes from them directly. I've read about these things happening elsewhere as well, but one thing always stays the same: it's always AB that's doing these horrid things. And in Texas, that was certainly true. We didn't see the 11th hour blockages coming from Heineken or from PE groups or from MillerCoors. It was only from AB.
Now, if it's just a "big corporations are bad" thing, I can sympathize with that but not necessarily always agree, or change my behavior due to that. For me, the AB thing has always been a "big corporations who use their size and money for the purpose of eliminating small guys" thing. IIRC, Coors has provided financing for lots of small breweries, as well as helping out in other ways. Heineken/Mahou/Duvel, etc, these seem to be big companies trying to wet their toes in a changing marketplace. In these situations, it's like a big company trying to stay big by adapting to changing trends, whereas with AB, it's always felt like "the market should change to fit us, not the other way around."
I could probably talk about this for hours and provide lots of substantiating evidence and **** but I'm hungover and don't want to do that.