I question any idea that big company takeovers of small, originally independent breweries is risk free or cost free for the beer's quality and integrity (surely Urbans don't think this anyway?).
Sometimes additional investment will work very well and spread the word and availability of very good beer. I take the point from
ViolentPanda on that. They have to be genuinely left alone though.
But other times, and there are examples, once decent beer will end up much blander because of the scale of its more popular/corporate version. The sheer ubiquity of certain beers can ring warning bells for me. I met the former head brewer of Sharps in September at an event we went to, he'd left them when Molson-Coors bought it out, and he had some interesting criticisms to make ... (not that Sharps were ever among my favourites, but I make a broader point)