Discourse is a Rails forum with a JS frontend. It's bloated. I don't disagree with your PHP experiences, you're extrapolating from:
1) your personal experience
2) mature software vs immature software
3) bad software vs good software
You can't say you're "not interested" in understanding the other side, throw out your own anecdotal benchmarks, draw conclusions from that, and then demand that others provide "non-synthetic" benchmarks in order to prove you wrong. Well, you can, but it doesn't seem especially objective.
1) your personal experience
2) mature software vs immature software
3) bad software vs good software
You can't say you're "not interested" in understanding the other side, throw out your own anecdotal benchmarks, draw conclusions from that, and then demand that others provide "non-synthetic" benchmarks in order to prove you wrong. Well, you can, but it doesn't seem especially objective.