It's good to be skeptical of reform attempts, but we also don't want to fall into this trap:

Gramsci shows that one of the main historical concerns of the Catholic Church has been to control the reading and the diffusion of Christianity, blocking the rise and spread of popular, autonomous and base level interpretations and thereby saving the purity of the historic doctrine... Many Marxists act the same way. Their biggest worry is the purity of the doctrine. Every time that historical facts challenge the doctrine or show the complexity of the practical operationality of elements of the theory, they deny that these elements are part of the story of Marxist theory and doctrine. This is, for example, what doctrines of betrayal are built on.

The "complexity of the practical operationality of elements of the theory" in the imperial core is that there has never been a successful socialist revolution here and there are no significant prospects for one currently. The most notable "revolutionary" movement in the U.S. right now is what, the PSL? No one has cracked the code of how to build socialism in the imperial core. It's not a betrayal to experiment with other tactics when revolution has failed (or never started) in your local context. It's also not a binary choice; you can support the most revolutionary group available and still do reform work to pay the bills, for example.

The touchstones for me are to not lose sight of the end goal (socialism, not kinder, gentler capitalism) and to be ready to move if a mass movement you weren't involved in takes off.