OP hardly is the voice of "classical arts." To get the minor issues out of the way first, if "it's strictly the blue-haired set the OP must be a blue hair, since "strictly" is strict about its meaning. Also, it is rude to refer to gay men by the ton-load, but if one sees 15 gay men in an audience one likely is well approaching the "tons" mark. A "popular lexicon" by historical definition would always exclude "classical music and dance," which were developed for the nobility and other people whose intentions were not to be part of the proletariat.
In fact, it is likely that the opera and ballet the OP is referring to is not "classical" at all, unless she is partaking of a steady diet of "Don Giovanni." Of course "classical" is a term popularly used to cover everything from Baroque to Glass, but since the OP seems to want to quibble about the meaning of "popular," we shall, too. Ballet and opera, after all, received their greatest popular attention after the classical period, and no one in his right mind would classify Puccini as a classical composer.
Now, for the OP, we must assume you are talking about fine arts, which extend well beyond opera and ballet for music, and into the visual and non-musical dramatic arts. While widespread interest in fine-arts music has grown and waned over time, the advent of cinema and recorded music helped promote divergences between the popular and the "refined" or "serious" forms. Even so, people such as Gershwin and Weill did their part to try to merge the two, and non-musical theatre has had somewhat greater success in some ways tipping towards the finer forms of drama.
Nevertheless, the heart of the matter is that the fine arts never were fully within the capacity or interest of most people. Pretending that everyone outside Vienna were humming Schubert (a romantic, not a classical composer) lieder once his popularity was established is silly. Italian opera and, to a lesser extent, German opera were more relevant to widespread audiences in the 19th century, but even there it was the growth of education and some improvements in the economies during parts of the 19th century that gave people time and know-how to appreciate opera. Without recorded music, people would listen to what they could, and that meant what orchestras were playing. For that matter, remember that the waltz was considered vulgar at first and not something that better people would admit enjoying.
Outside the development of operetta and related popular musical theatre forms, the fine arts always have relied on the wealthy for the economic basis of their existence. And that's the way it is now. The chumps who buy season tickets or "special offer" tickets for symphony companies' "accessible" evenings with John Williams movie themes aside, opera, ballet and serious instrumental music require monied support, and they get it, usually.
Major cities and many smaller cities maintain at least one ballet or modern dance corps, a symphony orchestra and numerous smaller music ensembles. Recorded music sales are not doing poorly. Empty seats always have been seen, as if "tons" of people would rush to listen to Natalie "Bullshit" Draper. They won't show up for Hindemith or Schoenberg either, OP. Do you?
Passion for the arts requires will, intelligence, patience and education. I love and live with all kinds of popular music, like musicals, like knowing current dances, and the rest. These things are necessary to live fully in one's time, so I don't put down popular tastes. But I do recognize that the fine arts simply aren't for everyone in the first place, not in the way that gets someone to the symphony for more than December's Handel. Music education has been in decline in many school districts for 20+ years. All arts organizations have education departments but that's not enough.
Finally, much of current "serious" music is as tediously academic, cynical, political and ironic as the visual arts are. The truth is that the arts are now often in the hands of the philistines. Look at the posts here, after all. Lazy sarcasm.