Oh, well, that's a different story, then. Interfering with sleep is justification enough for wishing to destroy the happiness and lives of others.

I guess if you weren't invested in the characters, it would stop being fun. But I thought that JK did that better than she did anything else. The writing, admittedly, was often sub-par and predictable, but the relationships and the characters and the beautiful vivid mental playground of a world made it worth coming back to.