You did not prove a thing, all you did by not providing a hide was have to turn the whole tank into a hide by keeping it dark all the time. So one way or another you have to provide a safe place for the T to feel secure in. Now if that's a hide or a dark closet, that's personal preference, but ether way to had to substitute lack of a hide by keeping the tank dark.Of course, I also have Ts with hides. It really depends on what you like, the T really doesn't care. No debates please. I really don't care if you think a tarantula NEEDS a hide, cause I have proven that wrong with my keeping.
Be careful with having any tank in direct sunlight, it can heat it up much faster then you think, and even with a flat decoration they can hide under you still might nuke your T.However, I always place a flat decorative item in enclosures so they have an immediate shelter against direct sunlight, it solved many problems and many used it as a startup base for their nest!
This approach makes a lot of sense to me; sure, T's are capable of living, maturing, breeding etc without hides, but an awful lot of them (esp. terrestrials) seem to prefer them. My G. rosea never leaves her hide except to drink/grab a roach, and my G. aureostriata hasn't left his hide in over 6 weeks (he'd better be molting, because it's webbed up tighter than a drum and I can't see inside). My P. scrofa freaks if I turn the light on, and uses either her burrow or her hide 75% of the time. B. smithi only uses hide to molt. The rest seem to not care for a hide at all; OBT lives on a silk mat high up in his fake plants (go figure), and my albopilosums burrow. I think letting the T decide where it's most comfortable makes sense.All of my T's are assigned hides in the beginning, and later I remove my hide if the T's decide they prefer making their own or that they're display T's, who seem to enjoy staying out in the open. For the record, with my T's anyway, G. rosea, A. seemanni, and A. chalcodes make really great display Ts. None of mine ever used their hides. I haven't had a P. scrofa, so I can't say with that one. And if the C. marshalli is anything like the bechuanicus and brachycephalus, it's probably webbed everything in site to make it's own special place and has no need of a hide.