Except most of the upgrades are strictly optional. Like redstone,f you don't feel like brewing potions and going out adventuring, you don't really have to.
Hmmmm, maybe I should look into setting up an Alchemy shop on the server.
For me, its the updates and additions that keep the game interesting. I only start to lose intrest in a game when I feel like I've done and seen everything. I recently stopped playing Torchlight for that very reason.