What? No you can't. I've been in hollow hills and they spawn almost no diamonds. It's redstone, gold, iron, and other common ores available in whatever modpack. You'd have to go to a Large hollow hill to get "stacks" of those ores, too. Hydras are far more dangerous than holllow hills, and with the progression in TF you can't just go kill one immediately. I don't remember there being diamonds in those either but if there are, having to kill a hydra is probably enough of a challenge to justify the ores? Keep in mind there are spawners scattered around inside hollow hills too. They're not just treasure piles.Does the ore removal in TF include ore generation in hills and hydra caves? Because thats the primary reason I dont like TF. those hills just have stacks of ores in them and the challenge to get to them is negligible. Heck with a magic map you can just seek them out and end up with chests full of diamonds.
I don't get the complaints about TF anyway. There's nothing cheaty about it, unless you count easy access to glowstone. It was dangerous before infernal wolves, and the ores were just as rare as in the overworld, weren't they? I guess seeing ores in caves is easier without taint covering everything, but it's not like it's easier- hostile mobs can't spawn on fibrous taint. You just get thaumic slimes from bats dying to taint, which are only dangerous when they're big.