Yes, it's beginning, but I think it's still a 95-99%-on model. AFAIK those miners only turn off the gears in periods of extreme demand surplus, when they're "ordered" to turn off operations by the electricity distributor, as a condition to benefit from energy credits (Riot case).

Anyway, I think soon we'll start to see miners doing the same but voluntarily chosing their on-/off-cycle due to them using the wholesale price (i.e. participating in auctions in the energy exchanges themselves, or with access to a tariff which follows the wholesale price - something already available in several European countries even for retail energy consumers). By the way this method would even stay relatively attractive if the "DAME" mining tax is implemented in the US, as the prices they would pay when they effectively consume would be low, and thus also the tax (Anyway I don't like the tax concept, above all own renewable generation should be always excepted.).

Of course, that's also why I will repeat this argument until somebody proves I'm wrong - but then I've no problem to admit an own error. But I think evidence is clearly pointing into this direction

I think you can't deduce from the risen hashrate that mining has become more profitable. Only that it stays profitable, but currently only for those who can afford efficient ASICs and cheap electricity. The hashrate increase is very likely largely a product of hardware improvements (Moore's law).

However I agree with you to disagree with MeGold666 here If profitability was that bad we would see a slower increase.