It's a bad idea, but orders of magnitude less of a bad idea than drunk driving. People ditching cars means less drunk driving (even if it means more drunk cycling), as well as less road deaths in general. That can only be a good thing.

If you kill yourself while cycling then you were almost certainly hit by a car, which is probably more likely if you are drunk cycling. But this is also the fault of bad cycling infrastructure and arguably the driver who cannot avoid another road user.

> It's just a bad idea all round...

Drinking alone is a bad idea all around.

Yes, better not to drink alone if at all possible.