Speak for yourself! If you know anything about music you wouldn't make such a stupid and blanket statement, but that's YOUR choice, not everyone in your age group. Yeah, I didn't grow up at the time of Matisse, Monet, or Mozart, yet that doesn't make me appreciate them any less. Just because YOU don't like or care for the Beatles, doesn't make ALL people of your generation think like you. People from all age groups, races and backgrounds appreciate them for their talent.
"because it reminds them of those times and brings back memories of what they used to listen to back then."
You really think that's the only reason why people like the Beatles? Really? I can like the Beatles, Rimsky-Korsakov, Mozart, White Stripes and the Velvet Underground, but not because of "memories" but because umm . . . I don't know . . how about because it's incredible music! I suggest you go to the library or a record store and just listen to music, ALL kinds of music. There's more to music than just what's out there now.
People appreciate the Beatles because they appreciate music. I know it's a hard concept, but you might be surprised that's it true.