Oh I totally agree.

But voting liberal (eg Dems in the USA) gives us more time to find a solution. It's not the solution, it's just a stalling tactic. Even when they're trying to block opportunities, it still results in relatively more opportunities than otherwise. I think there is value in that.

There are times when spoiling a ballot or even voting the other way is good, it sends a message which may (unlikely) cause a shakeup. But to simply never participate just accelerates the destruction.