I don't think progressives would ever call Harris "incredibly progressive". She's kind of a middle of the road Democrat, interested in the energy that comes with progressive causes, but who will water them down or abandon them if they encounter resistance. So "doubt" specifically is a very good descriptor for the viewpoint of progressive organizations.

I do agree she was better than most of the floated alternatives, so a primary is kind of a pointless ask. It's not like there was a Warren-level progressive in the running. Harris is a fine candidate, with potential for progressive upsides, and more importantly she was always the only real option for a successful replacement. And thus far she's demonstrated an interest in motivating and listening to Democrats, which is a big vibe change from Biden's desire for bipartisanship and prickliness whenever anyone on the left would ask anything of him. Middle of the road Democrat >>>>>> centrist.