Derek wrote: Could be a matter of history. Very few North American brewers survived prohibition, so they didn't need a quality product to compete (and almost anything would seem to be high quality after the bootleg brewing).
Maybe it's been like this for 70 years (which is a long time in North America, yet only a small part of brewing history)... but hopefully our history is changing.
America's regional craft brewers (and even some of Germany's big macro's) are showing that you can still have a successful business making large volumes of a quality product.
Not that I'm advocating big business. You still can't beat fresh, local craft (assuming it's good).
But I'm preaching to the choir... everyone here knows that the North American brewing industry is seriously messed up!
I may be off base here, but I see the entire North American macro market in the same light as the factory food industry. Prohibition had little to do with it, beer quality went down the tubes at the same pace as food quality; Coors Light = Cheese Whiz (Coors Whiz?

Sloooowly North Americans have started to care about what they put in their bodies and what it tastes like. Localisation is a big part of that. Organic foods start local and many have spread into national brands. There is money to be made in quality today just like there was money to be made in petroleum based crap over the last fifty years.
Size is not the enemy, but quality control may be a challenge and accountants might cut corners ingredients. As long as consumers are vigilant and vote with their dollars, there is room for 'big micros'.
Do we think Joe Sixpack will care? Probably not, Joe Sixpack feeds his kids Mc Crap and calls it a treat.
I like to think brewers like Black Oak & Heritage are our little quality secret, but at the same time I wish all the possible business success on on them. They may care, but they also deserve reward for their business risk taking. Besides, the example only encourages more brewers to join the fray.