When we found out when this was coming to our area and were discussing getting tickets, our daughter (who was obsessed with the soundtrack) said that she wasn't sure if she wanted to see it because she'd heard that it was becoming one, big, audience sing along. I'm grateful that that didn't happen here because I do think it's rude. In fact, I think they could have very politely announced at the beginning of the show that while they were so grateful for how much people loved the show and had come to see them, that they would request that people not sing along so that others who may not know the lyrics could hear them. Of course, they shouldn't have to make that announcement, but some people don't think.
For anyone already loves the show and for those who love it after seeing it for the first time, this "behind the scenes" book is a lot of fun and very interesting:
Hamilton: The Revolution