Enforced sleep deprivation and things like that are forms of torture by most definitions*. The fact you do inhumane things to your own armed forces doesn't make it more okay to do them to other people - especially when, as this report has pretty clearly noted, you get basically no benefit from it. It's very simply a form of cruelty that has no reasonable evidence to back up its usefulness.
*See, for example, Chinese water torture, which I'm sure the US government wouldn't consider "torture", but pretty definitely and objectively is.