I don't think the goal for ABI is to trash the products or otherwise affect the production quality of the beers. Rather, it seems ABI is looking to cash in on the craft beer movement and by having a portfolio of respected craft breweries they can offer a total package for their distributors to sell with their mainstream lagers plus a mix of European imports and domestic craft offerings.
IMO it's really less about competing against the local craft brewery and more about competing against the larger craft brewers who are competing for tap handles in places ABI and MillerCoors have traditionally had little competition. If they can convince Chili's and Applebees to take out the Sam Adams or Fat Tire handle and put in Goose Island or Elysian then they can control all the taps. They can also sell a complete package of handles to sports bars and other places that are expanding their beer offerings beyond the, "Oh we have everything! Bud, Bud Light, Miller..." but don't have much understanding of craft beer or any real interest in understanding it except knowing they need to sell it.