Absolutely not. Actually, I've heard more stories from my customers of snakes doing better after being moved from a cage to a tub. Better at eating, shedding, breeding, etc.
A large enclosure is very complicated when it comes to providing the correct environmental conditions when it comes to ball pythons ... tubs make it a lot simpler and in the end, providing ball pythons with the correct temps and humidity is the most important aspect of keeping them successfully.
If you want to stimulate them, regular handling and exercise outside of the enclosure is the best thing to do whether you are using cages or racks.
Hope this helps.
-adam