It'd be a legitimate argument if Greg treated other mods the same way. As is, he has basically copied (although poorly) the OmniWrench functionality and put in an arbitrary limitation for his own machines. So it's less about "I want it to work this way" and more about "I want my mod to be the only one people use for anything."
Do unto others and all that...
king lemming...quoted...me?! *faints*
I do agree with you there though, i do wish greg wouldn't invade other peoples mods, it makes it so much harder to fight his corner as i do love the mod due to its high amount of endgame content.