I agree that SJWs don't seem very interested in making people happy (in fact I think this is one of those Moloch situations and everyone is actually producing unhappiness because of their incentives inside the situation) But SJWs do rely on general happiness goals in their audience. I do also think a lot of Social Justice thinking started out as a genuine desire to help people and make them happier, regardless of how that goal turned back on itself do to inconsistencies in other places in the philosophy.

I see it as a set of originally well-meant goals that later spiralled into virtue-signalling competition. Now they run on the classical cultish behavioral patterns.