Blockland did not have any kind of shaders pre-v21. It had a rudimentary shadow system, but that's far different from shaders. Shaders were completely added in v21 and the calculations for terrain shaders would be far too stressful on the engine and too much work for Badspot and kompressor to work on. Not to mention they were outdated and looked like stuff.
Personally; I liked 'em, it was the feel of the game before, but Badspot made an executive decision so there's really not much we can do about it. Having an up-to-date looking game improves sales and consumer interest.