Um, does he not realise that the profitability is constantly adjusting and will balance itself out? If it's too expensive then miners fall away until it attracts miners again.
It would be nice to see an alternative to PoW that does the job though. There'll come a point where comparing the electricity consumed by the banking world won't cut it any more.
Um, do you realise that this is a completely pointless observation?
The reason why proof of work secures the Bitcoin network is because of the "work" part

You're essentially asking for something for nothing, security for zero effort. You may as well fantasize about time machines or anti-gravity boots.
So the "using too much electricity" rhetoric is no different to saying "Bitcoin is too secure". What exactly do you people want, insecure money?
I've wondered about this before. How much security do we really need? The hash rate is a measure of security, but it is so exorbitantly high that no single individual will come close to it attacking it.
If half the miners dropped out, like they just did to go mine BCH, would that be such a bad thing? Difficulty will readjust, BTC will still hum along. Eventually the only thing that will make BTC profitable will be if enough people adopt it and transaction fees pay the difference in electrical costs since block rewards will drop off.
Am I missing something? Of course we want security, but I really don't think we need this much. From my perspective, we are in the mining bubble stage. Unless hash rate drops so low that it could be attacked, there shouldn't be a real need to worry.