If a person is disastified with the Republican party and refuses to vote for them any more, would you rather that person stay home, vote third party or vote for the democrat?
By your logic, staying home or voting third party is the same as voting for the democrat - it's not.
It's all bad, and it's all whining, and it all costs us races. I didn't see any RATs staying home and not voting for any of their candidates, even though many of them are more moderate than they would have prefered. Nor did I see them wasting votes that would have brought them victory on third-party candidates.