> Why is there so much sympathy for ad-supported sites on HN but when other industries with obsolete business models are brought up (like record companies) it's all about "disrupting" them? Have we given up on finding better ways to support content online?

Because there are a lot of users here who run websites and see the business model 'from the other side'... and almost none who work for record companies.

There are other reasons, but that's a big one.