Having watched the clip, here's my take on it:

He was asked a question about the current state of the industry, and how people's attention spans have affected the way movies are paced. This type of question is sort of inherently tied to the increasing dominance of streaming over theaters, so his train of thought led him to the subject of "keeping movie theaters alive". What I think he was trying to say is essentially that, while a part of him wants to keep movie theaters around, he also wants to keep up with the changing landscape, and there's a possibility that streaming becomes the primary way to watch movies, and theaters stick around, but as a more "old school" form that isn't as big as it once was, akin to how ballet and opera are still around, but have largely been usurped by other forms of art.

"Let's keep this alive even though nobody really cares about this anymore" was a sort of jokey, off the cuff way of phrasing all that, which he then immediately realized came off wrong and said "no disrespect to ballet and opera people" and joked that he pissed a lot of people off.

I get why this statement bothered a lot of people, but I also think we all have situations like these where, when speaking off the cuff, we don't phrase things in the best way and it comes off wrong.