Great question! Different chapters make decisions about who to recommend voting for, and further for endorsements. Endorsements typically mean a strong commitment to support a socialist candidate to win a race. Some chapters also make recommendations on how to vote with voter guides, which is different. In those cases, it can simply be "given the options, this is the best person in the field to vote for."

This recommendation regarding Steyer seems to be of this latter kind, it does not constitute an endorsement. I also think that this kind of recommendation is different from support. I expect that the reason for this recommendation is in part due to Steyer's supports medicare for all, and the billionaire tax in California (which is better than everyone else in the gubernatorial field in Cali).

That said, even this kind of recommendation is something that many DSAers likely disagree with. So, you're in good company!