I watched a TV series named Generation Kill based on the experiences of an embedded reporter during the invasion of Iraq in the 2003.
The US Marines in the series often complain about lacking essential supply such as batteries, decent toilet paper, baby wipes, etc.
When asked why it is like that, an actor playing the (real-life) marine Cpl. Josh Ray Person said:
To keep us angry. If Marines could get what they needed when they needed it we would be happy and wouldn't ready to kill people all of the time. The Marine Corps is like America's Pitbull. They beat us, mistreat us and every once in awhile, they let us out to attack someone.
Though it's more like a satire than an answer, it still sounds quite convincing.
Do the US Marine Corps sometimes deliberately keep their soldiers under-supplied and uncomfortable/inconvenient in order to keep their aggressiveness high?