Those of us who support reducing regulations on housing are often accused of being libertarians or market fundamentalists. Some of us certainly are, but not most.
There isn't any contradiction between being a liberal who is normally supportive of industry regulation but opposes single-family zoning or minimum lot sizes or occupancy limits. That's because, in sharp contrast to labor or environmental standards, most housing regulations opposed by YIMBYs don't have any social welfare justification. For the most part, zoning doesn't protect anybody or anything that progressives tend to care about: the environment, the poor, etc.