it just means they agree with everything that is said
On the contrary, one of the reasons I'm fond of the community is the rational debates.
usually main-stream liberal ideology
Hubski is predominantly socially liberal because the educated demographic is statistically socially liberal.
It's not, however, predominantly fiscally liberal. There are quite a few fiscal conservatives here.
I participate in a number of websites and communities that are socially liberal, but not rational or intelligent. For example, Imgur is socially liberal, probably because they attract the young and international demographics. But I would hardly call the community educated, intelligent, or rational. Nothing against them; it's a great place for visual entertainment, just not intellectual discussion.