Tossing in that we do have pets specifically tied to plant/farm-y themes - the Wilt Florana, Harvest Leumoo and Crops Nyghtmare come to mind. I also like the idea of items having different properties due to a pet's coloration.
Granted, I am keystone-poor, but I'm fine with start-up fees too. I'm also a fan of generalizing the output items of pets or adding a lot more species to the item output pool, for the same reasons people have stated previously. I didn't use too much of the farm before it was nixed, so I feel like there's not too much I can contribute.