I have found this discussion interesting. I don't think I've ever taken part in a 'trans thread' before but do like to use Mumsnet to satisfy my annoying pedant tendencies sometimes.
The meta-message, if I may be so wanky, seems to me to be about asking open questions, listening and reflecting, even more than about use of language. (Other people do things for reasons we hadn't thought of shock!)
I've shown that I think the OP's connection with 'peak oil' is meaningless. (I suspect that perhaps she and fellow environmentalists were so focused on finding a diverse, low-carbon solution to that problem, as opposed to a continued fossil e.g. fracking and nuclear one - their real foes - that they forgot that the peak oil scenario was not of their making).
But, that fallacy can easily be cast aside and the OP's point about language made regardless. The idea that 'peak something' in the contemporary sense means 'I've had too much of that and wish it to diminish' and that that could be understood as being about people rather than ideology.
What I'm reminded of most though, is discussions in the workplace, one where we have both internal and external audiences. Where some terms are clearly technical and not what you'd use in public communication and others do a good public job without making perfect technical sense. You always get some self-important smart-arse who waxes on about a specific term being flawed because it doesn't work for the audience for which it is not intended (or has no idea about what people outside the technical audience respond to). Everyone else thinks 'duh, just use your judgement, social skills and think about who you're talking to, like everyone else does'. And 'ffs you've just taken up five mins of a half hour discussion that we could have used for something useful'. Again.
Anyway, I love avocados and have done since long before they were fashionable, maybe even before some of you were even born. If I can't have avocados in your preferred version of future imperfection, I'm not coming.