Mine doesn't hide either. I mean he goes around some plants and other stuff, but it doesn't like sit behind something and hide. Besides when i'm changin the water he is a scaredy cat then and hides while his mate the acara will attack me even though she's 2 inches compared to him being 4.
Idk about the whole bare tank idea, I think the terror will just be to scared having nothing to hide around. I mean even if he never hides he will want something to swim around and explore, not just a tank with nothing. Would you want you bedroom to have nothing in it, I highly doubt it. I don't have alot of things in my tank a few fake plants af ew rock formations that I made and thats about it, it does the job though.