And then, Opera is one big piece, though performed with a large group of (most often). That is, music in one direction, one style. This is perceived with difficulty, I want diversity. Moreover, in each Opera there is a part, for example, a popular (I was on classic Opera), and not.
But the main, of course, training and education. If you have been accustomed to classical music since childhood, you understand its beauty, the Opera Aria will be perceived as aerobatics of performing skills.
But I must say that not all famous people like Opera, so it has collected a lot of mocking quotes on your account.