Obviously, if mining is not profitable, which seems plausible, then WHY? Even if they are taking the gamble that the rate will rise beyond break-even in the future (someone mentioned $717 before) , it would be easily more profitable to just buy BTC for the same investment at the current rate (not to mention the effort).

The only reasonable explanation is that there is something we don't know.

I think it is this:
They made a secret deal with an ASIC manufacturer: They buy non-profitable ASICs, and share the profit. They can pocket that money themselves and maintain the unprofitable mining farm. ASIC manufacturer is happy to have a customer for nonprofitable equipment, and therefore willing to sacrifice some profit. Mining operation doesn't care it is buying ASICs at a high price, because they will get a fraction of that margin. They show off on social media to attract more investments, with which they buy more unprofitable ASICs -> more money for themselves via the secret deal.

Eventually, the whole operation will collapse as investors realise their investment doesn't yield sufficient returns, but the miners don't care a they already made a profit for themselves.