Why the same "old" operas?

Now that The MET has officially opened, the opera critics come out in force and the love it / hate it / don't understand it wars begin with a vengeance. The new Tosca was a case in point. No two people seemed to agree about anything. This is not exactly bad for the MET. Critic wars make news. And Peter Gelb certainly gets his opera company in the news. I think this is healthy for the venerable company and good production (Madama Butterfly) bad production (Sonnambula), people are coming and noticing. The war of words between Zeffirelli and Bondy certainly didn't hurt. (The comment that Zeffirelli was just merely "...Visconti's assistant" was one of the more cutting put-downs of recent years.) Of course, all this talk about productions and (even) singers doesn't really disguise the fact that the rep is still pretty set in stone. And we know this and occasionally complain about this but to no avail. The Lulu's and the From the House of the Dead's are few and far between (as are performances of them.) Even a piece like Hamlet will swoop in for a few seasons and certain singers will triumph in the two main roles and then it will fly right out of vogue just as quickly. And I doubt seriously that even the great artist Renée Fleming can make Armida a popular recurring addition to the roster. None of this is new. The reasons are myriad but one of my strong beliefs is people have to be "taught" what is good or bad, and no one is "teaching" Armida. I learned from others (fans, singers, teachers, etc.) the works that were considered "great" and I set about to understand why. "Learning" Le Nozze di Figaro is relatively simple. We've heard this harmony and these kinds of melodies everywhere, whether we know it or not. The more "debated" or shall we say, less performed and recorded works I had to discover for myself. And I worked at it and studied them and tried to learn the "language" that each composer was using. And I discovered quite a few "masterpieces." But I sometimes fear I am in a strong but wavering minority. Your majority opera listeners don't have the time or inclination--they want ready made "masterpieces" or at at the very minimum, lesser works by confirmed "geniuses" (mostly from the 19th Century unless it's Handel.) And often they take "genius" on faith and accept the faulty syllogism that if A) a composer is a genius and B) he wrote a piece in his adulthood at the "height" of his powers then C) the piece must be a "great" piece. So they listen and they listen until they "know" it by the time they hit their seats. And they accept as fact that the mutually agreed upon "masterpiece" is one. Which leads me to my next blog...but first, what do you think? Any answers to the age-old question? Any solutions?