Note that the notion of preference must remain unqualified given limits placed on the ability for people to express what their preference in fact turns on, and given limits placed on the capacity to measure it.

Sorry I'm not really sure what you mean here.

I understand your overall point, however in general in society we do place limits on the power of the majority when it comes to things that affect a minority group (or anyone really). For example if it would make 98% of the residents of a racist rural town happy to ban all black people, we still wouldn't allow them to do it even though it's their democratic will. I think this is referred to as "tyranny of the majority" although I could be misusing that term.