I don't know if defeatist is the right word, more like cynicism. We all seen how poor Democrats in the past has performed, and we're seeing many of the same actors not taking the reins.
For instance, you mentioned rent strike. People are simply not going to do that en masse. You have scores of people barely surviving before the pandemic hit, and they're now drawing on whatever reserves they have. What's the difference between a rent strike or not paying rent because you don't have the money in the first place? When the first eviction letters get sent over the summer, spreading potential carriers to have to move with relatives that may be doing a bit better or becoming homeless, getting more people sick.
The House didn't include any notion of workers pay that even Republicans can back precisely because of that. The house Dem leadership is scared of what is supposed to be one of their priorities actually enacting into law because they don't want to make people expect government can make their lives better outside the margins. The fact that they're pushing COBRA subsidies over getting people signed up for Medicaid, or even ACA expansion is such a terrible policy (And the most expensive!) shows they're so scared of the health industry that this current Dem leadership is never going to improve the status quo.
If it's a messaging bill, they're showing what they're messaging, and that's they don't want to use federal government as the tool it needs to be.