"The left" is an umbrella term for all kinds of causes that don't all share the same concerns, values, or goals, while "progressive" is basically a replacement term picked up once right-wing propagandists had poisoned "liberal" and "left" enough that some people gave up using them (which was a dumb move IMO). Environmentalists, labor rights activists, gay rights activists, and anti-war activists fit under the umbrella but often have little in common, and can have stark disagreements. I'm going to guess you don't identify as someone on the left, and so you get your information about what's happening from filtered sources rather than spending time paying attention to the debates, bickering, and disagreements that various sorts of left-wingers have, rather than taking a detailed at what's actually thought or discussed. I understand, I ignore Tea Partiers, though I also try not to claim they are a monoculture, since I know I don't really know much besides what the latest staggeringly stupid thing one of them said was, which is certainly not representative. That's the problem with Internet echo-chambers, they radically warp perspective by limiting what information you see as well as bias its presentation, and give an reductionist illusion of some single entity when there are many diverse factors in play.
Alternately, you could just look at the actual cases the ACLU takes, which often enough support people and causes that aren't darlings of some faction or another on the left.
For the record I was against Eich's firing (and know a number of leftists who were similarly against), I donate to the ACLU and the Sierra Club, and used to be an anti-war protester long ago. I also am enough of an exception to your generalization that you might want to reconsider your stereotype.