For a brief guess, I would say that they're basically just saying that the inside of most museums and art galleries are still quite pleasant (generally favourable) even though many of them are rather crowded and you have to pay to get in. They can still be nice places to visit.
Suggesting that a particular piece or object is "important" can make some people feel bad that they've never heard of it or that they don't know anything about it. People don't feel so bad if they walk around a gallery just looking at things and believing that everyone is looking at them from the same general standpoint - ignorance! However, if we go to a museum or art gallery already knowing that other people (experts) have said that a particular piece is "important", it can be difficult for us (the uninformed viewers) to go and look at it and not understand why it's important.
Student or Learner