Is learning from a record significantly different in principle to learning from a braodside?

Yes. It's a canonical source. Not only that, it's a canonical source that sounds better than you - only a minority of people who buy a record will be motivated to sing the song (for other people to hear).

The only reason people didn't is because the technology wasn't around.

I don't dispute this for a moment. I'm not saying technology's evil, or that people have been corrupted by it. I'm just saying these things have happened, and they've made a difference.