Solarpunk is still very communitarian with a healthy dash of anarchism. The focus is on sustainability and using technology to support both human and ecological flourishing rather than that of metahuman entities like businesses, states, or organizations.
What you see as "doomsday pepper shit" and "subsistence farming" is radical anticonsumerism. People wanting to support themselves and each other rather than make money and buy products.
Solarpunks aren't luddites or antisocial, quite the opposite. That's what you see to be missing.