This depends a lot on the beer for me. There have been many brewfests where I was glad to only have a 2oz pour...
I've poured 2oz samples out.
One of my favorite brew fests is the Southern California Homebrew Festival. 35-40 brew clubs each with an EZ-UP tent and their bar, typically serving at least 10 and often more unique beers throughout the course of the day. So 500+ unique beers on tap. It's about an 8 hour fest, unlimited pours, so you need to moderate.
I've had some amazing beers at the homebrew fest. But it's homebrew, and there are certainly quite a few poured out during the course of the day. After all, it's a full day of drinking, and I'll usually ask for short pours anyway just to keep myself from getting too drunk. I'm certainly not going to choke down substandard beer when I can be spending my waning sobriety on things that actually taste good.