The problem is the moment someone chooses to fly in a private jet, they lose all credibility in calling for anyone else to curb their own consumption.
So if the individual is, as is the case with Twiggy, trying to actually develop things and make them work then there's no real conflict there. He's not calling for an end to anything, he's just saying let's see if we can find a better way and he's putting his money where his mouth is.
In contrast Cannon-Brookes has called for things to be ended, quite rapidly so, whilst doing not much to replace them. He's called for an end to specific coal-fired power stations but I sure don't recall him backing any deep storage projects as part of what's required to replace them. That's the opposite of Twiggy's approach that starts with solutions.
So one's doing the equivalent of inventing computers and reasoning that once you've got one of those, you won't actually want a whole range of things anymore so they can be done away with. The other's threatening to take away your typewriter, cassette tapes, CD's, books and the postal service without a replacement.
Unsurprisingly the former's faced no real criticism at all, whilst the latter's faced plenty.