They certainly do, but I have a different goal from theirs. Blizzard's goal is to maximize the profits of the game. My goal is to make the game more fun. While those goals seem like they ought to be in harmony with each other, Blizzard has other ideas, namely forcing the progression game into ever mounting levels of repetition. Hence the continual innovations to come up with a new way to walk through a corridor killing monsters for the same rewards.
That's not to say that all that Blizzard is doing is garbage, new tilesets and monsters are always appreciated, and are certainly far more labor intensive than adding new items to the loot pool, and of course the Necromancer is a good addition. I'm honestly surprised it took them this long to decide to add another Hero. DII: LoD added 2 new Heroes, and was a huge success, in fact its innovations were arguably the reason we remember DII so fondly.
But at the end of the day, banner icons, portrait frames, vanity pets, and transmog items do not bring the boys to the yard. Gear and content do. So yeah, I'd like Blizzard to put on their big boy pants and do things that are hard because they're the right thing to do, and I don't really care very much whether it's hard or not. My job is hard too.