I love classical music but simply cannot stand operas in their entirety. Some songs are certainly magnificent vocal tours de force (like the Queen of the Night song in The Magic Flute, and the Flower Duet in Lakme). But for the most part operas are just hours of unnaturally high-pitched, incomprehensible singing (often people singing over each other and creating quite a cacophony, hard to understand the words no matter what language they're in, and having to look at surtitles is distracting) that isn't pleasing to the ear, barring one or two memorable songs per opera.
I say this as someone with years of classical music training and as a lover of symphony orchestra concerts, choral and solo singing, dramatic theatre and musical theatre. I will gladly sit through entire symphonies or Shakespeare plays or ballet performances or musicals. But entire operas I find intolerable!