It's a very interesting question, and I have wondered for years:
What percentage of "classical music lovers" would also identify as "opera lovers"?
As for me, I first became really interested in classical music in my late teens (late 1980s), and I quickly found Verdi. I used to listen to Aida, and, in later years, La Traviata, and Don Carlos quite a lot. I also really loved Bellini's Norma, Rossini's Barber of Seville, and Mozart's Cosi fan Tutti and Marriage of Figaro, and Handel's Julius Caesar.
I never liked Puccini--sure, he wrote some beautiful arias, but for me, the operas overall lack much musical interest. I also dislike excessive sentimentality in music. Hence, I am not a fan of verismo in general. For reasons I am not clear on, I could never get into Don Giovanni, Zauberflöte, or much Wagner other than Lohengrin.
I have gone through at least three or four major opera periods since the late 80s, but the latest one for me was a Lohengrin phase in the mid-2000s. Since then, I have listened to very little opera.
For one thing, I have become increasingly interested in Bach's music, baroque and earlier periods, and the pipe organ. I have lost the attention span to listen to opera, when I always ask myself, "Would not this time be better spent listening to Bach?"
Also--and this is the main point I suppose--I am very little interested in an opera's plot, the libretto, the characters, the setting, or the costumes. I am not a fan of the theater in general.
As for watching a play (or even a movie), I would much rather go to a museum and sit in front of a Mark Rothko for an hour, or go to the beach, or look at a tree, or do some photography. The operas I like (liked) were almost entirely for musical reasons.