When studying the history of "Western" Music, the Classical Period in considered to be roughly from 1750 (when J S Bach died, thus ending the Baroque Period) to 1820. The term "Classical Music" as used now, probably came about because the uneducated listener was sort of aware that the orchestras in large cities often played symphonies by Mozart, Beethoven, Hayden, et al, who were commonly referred to as Classical composers because their works were composed during the Classical Period of Music. So, any music played by an orchestra began to be referred to as "Classical Music." The genre might be more accurately called "Classic Music."
So, if works by the greatest Composers of the various periods in the history of "Western" Music are the most commonly heard, it's bound to be pretty darn good sounding Music--so it likely is quite appealing to a large portion of humankind who hears it.
Then, when you learn a little bit about the people who wrote the Music, you might be even more likely to appreciate the joys and the troubles they lived through, and the emotions which you might feel when listening the their Music.
Or, a lot of the Music is just plain pretty to listen to.