1. I'm not seeing the causal link between the flag and the symptoms. I often find "Chrome" "causing" the same problems, but typically you can judge from the memory use that an errant tab is allocating the world, and you've started drawing on swap, which of course slows things down. But here we've cropped the memory stats out of the screenshot from top (for the system as a whole; we can see a few processes consuming a few hundred MiB, but Chrome loves processes, and there could be several more below, and summing RAM usage from processes is a deceptively tricky beast), and I can see nothing to prove that the field trial is even to blame.

2. You get the browser for free. If everyone adopted this same attitude, Chrome would not be able to do real-world A/B testing on features; what should they do instead, just release it all or nothing? You might have been unlucky today, but perhaps tomorrow someone else's misery provides the needed data to prevent a bad feature from going out.

3. Vote with your "feet", and switch to Firefox? (or one of the other myriad of browsers out there…)