> I'd love to discuss the substantive comment I made about
> energy consumption and X86 v. PPC.

Nobody's stopping you from discussing your own comment.

> I can't entirely ignore when someone blows off the substantive talk

As far as I'm concerned, you are free to discuss whatever you feel is substantive (e.g. "energy consumption and X86 v. PPC"). Don't act as if I was somehow hindering you from doing that. I'm definitely not.