The issue isn't black and white to me (except with AB-Inbev), and my issue isn't the size of the brewery or who owns it so much as what the strategy of the company is. AB-Inbev has made it painfully clear that they want to squash the craft industry, period. If they had it their way, bud/budlight/michelob ultra would have 100% of market share. And their strategy to kill craft beer was two-fold: 1) by flexing their (illegal) distribution monopoly muscles ("100% share of mind"), and 2) by buying craft breweries, more often than not cutting back on experimentation (exception being Goose Island) and flooding the market with the more mundane offerings.
At the same time, I will never begrudge a craft brewery for "selling out". I don't hate John Hall. He built an amazing brand and an amazing brewery and got paid, good on him. I just don't want to buy that beer anymore because I don't want to support AB-Inbev's mission.
I'm not anti-Boston Beer Company or Yuengling (granted, I don't personally drink any of their beers). BBC and Yuengling are still independently owned, they have just become massive breweries. Generally, nothing wrong with that, and BBC in particular are still extremely pro-experimentation (e.g., Utopias).
As a former LA resident, Firestone used to be a staple of mine. When the Duvel investment came in (with them and Bouleveard), I was skeptical but didn't write them off. What has actually turned me off to Firestone more was their first batch of Parabola after the investment & first brewed outside of Paso Robles (actually brewed at Boulevard, which also made me skeptical) was terrible, and they didn't have the balls to say "yep, we ****ed up this year's bathes, sorry guys". They continue to pretend like it's a great beer (it isn't) and pour that vintage at their taprooms pretending like it's aged well (it hasn't). So that to me was a sign that they are no longer a craft brewery that's all about the beer and being upfront with their customers.
EDIT: I forgot the recent acquisition of Dogfish Head by BBC. I'll admit, that scares me a bit, but I want to see what happens first before I write either off.