I've asked a lawyer about this general topic before.

I'm not quite sure if he was merely protecting his fiefdom by wanting to make writing out legal documents as confusing and incomprehensible as possible, but he said that the complex and formal legal language that was tougher to simply read was the equivalent of complicated defensive programming to ensure that "edge cases" in code that weren't handled properly didn't exist.

If you write out terms of service in simple and plain language you might miss something, or a court might find some statement inadmissible or interpret it differently than you intended.