Yes, it is, because you are exploiting the fact, that the AI can't handle such things liked blocked pathways. Same goes in my eyes for placing tons of explosive barrels around the AI, because in reality no enemy would not react to barrels appearing around him out of nowhere. It's one of the issues I have with sneaking, it's to broken and makes to much cheese possible.
But a solo run is kind of a cheese run from the start, because soloing is not much of the meant way to play the game.
So if you want to 'cheese' it is up to you anyway, same goes for people who save scum all the time. The problem is, when people cheese around and then say: The game is to easy, make it harder. All those who don't want to cheese or don't know how to cheese would suffer from it. ^^
