"Crypto winter" doesn't refer to the fact that half of the world is in the "winter season" climate currently but rather a time-period (traditionally lasting longer than a climate "season") when cryptocurrencies prices are at a downturn.
"winter" implies there's a forthcoming "spring". Parent is suggesting the possibility of a permanent impairment, that crypto may never "recover" to public interest and price levels seen in the last few years.
