You can't just take the part that makes you money.

That's actually the entire point of capital gains.
The government wants to take a cut of all your winnings but they refuse to take any of the risk.
They want to tax every gain and subsidize every loss.
They're just taking that to a nonsensical level with this one.

dumb government's decision to boost cap gains tax to 66%

You know everyone else in the world pays on 100% of their gains right? :D
Just checkin