Minecraft is hard to enjoy. The reason being is because with single player, you're basically spending all of your time and effort for nothing. Of course, that goes with any game, but Minecraft specifically. You're creating all these wonderful (or not so wonderful) pieces of art for no one to see unless you upload them to YouTube, and let's be honest, how many views do you think you will get?
With multiplayer however, you're able to show off your achievements and effort to others. The only thing though is that eventually, that server will get shut down and all that time and effort you spent on Minecraft is gone.
That's why I quit playing. I was tired of spending hours for nothing.