To be frank, I think it's because those who are highly educated often believe they know what's better for a person than the person does; economically & politica

To be frank, I think it's because those who are highly educated often believe they know what's better for a person than the person does; economically & politically speaking. I'd say it's more that they think they know better than tradition. They have the best reasoning skills and the most formalized evidence, which are of course better than generations of trial-and-error and heuristics and stacked biases. In terms of acceptance of minorities, especially (gay, trans or just ethnic) I think that liberal mindset comes from an academic need to include minority opinions into discussion. With the history of things like women having to write under male pseudonyms and people with the wrong opinions getting shut out ("scientific progress happens one funeral at a time"), this probably comes from somewhere else. I'd say it got fashionable somehow and then got stuck in a positive feedback loop.