I like humanists and athiests much more than you do - and I'm less sweeping and less certain in my criticism of socialistism.
However, I do have big problems with current left-wing political thought...I can't stand political correctness. More generally, the Left has a basic problem; at bottom, they're trying to justify greater rewards for the meek, the weak, the dumb, the unlucky - life's losers. Not an easy task. Some very, very famous people have tried and failed on this one.
None-the-less Leftists intellectuals, if they're capable and good at their job (as opposed to incompetent, foolish, and intolerant) deserve respect.
Can you give me an example of left wing thought that is worthy of respect even if it isn't current?
I can offer some possibilities: the anti-Jim Crow movement of the 50s and 60s -- but this was really started back in the 1800s by Republicans, so I consider it an ethical issue rather than liberal or conservative. Welfare -- but this goes back at least as far as jewish law, which mandated "leavings" for the poor at harvest time.
I would argue that most of the issues with which liberals justify their supposed moral superiority are neither liberal nor conservative. they are matters of personal character.
I wouldn't call someone who is weak, meek or unlucky "losers." However, I do agree that political correctness is an attempt at social coercion. You should consider that, because frankly many points of political correctness reflect the viewpoint of socialists and atheists.
I agree that everyone deserves respect.