Volunteers talk politics but don't talk Big. They seem to sense that it is ineffective for their job. Big talk may undermine the utility of what they are doing. Sophisticated arguments may alienate some people who may feel insecure to begin with. Activists talk a lot but disguise their identities as moms.
Activists differ from volunteers in that they talk to each other.
Here there is a need to distinguish between internal talk and external talk. And of course, you can have the bitterest fights among people who think like you. But activists need most CARE in talking out in order not to alienate, hopefully to mobilize, the general public and the institutions in charge to their cause. For both it is functional. Finding a place in which genuine political conversation goes on.