I mean the game has changed so much. I personally wouldn’t want to play the exact same thing as classic for 15 years. The fact that we try new things, whether they work or not, keeps it fun and interesting. There is also still plenty of challenging content in retail. I would argue that there is content tougher than what classic will be, but that’s just me. They’re both fun for different reasons.
It’s kind of like when you love a bands first CD, so you buy the next one, and the style is different and you don’t like it. This happens with everything because if you do the same thing over and over for 20 years you’ll lose interest from others.