Perhaps it is my regional culture for cards. I live in Northern Michigan and growing up I have played countless card games. Cutting the deck has never been about trust, it is more just how a card game is played. I can kinda see how people might be offended by cutting a deck. To me, it is more reflected to the deck owner. I give no fuss about people cutting my deck to show I am not cheating. If someone gave me a huff about cutting their deck, then I would get suspicious.
These type of games can get rather emotional for some people. First off they invest their precious money into the game. They spend countless hours assembling and painting their miniatures. Then they think of an awesome list to destroy their opponent. For some people, the temptation to have the edge of their opponent becomes too great. I am sure we all know that guy that throws things when he is losing or that guy that tries to slip in a few extra points where no one will notice. Fortunately I never experienced these things with Malifaux, just Warhammer.
With all that in mind, I just made cutting the deck a habit as a show of good faith and frankly a deterrent for those players hoping to get a slight advantage. But it is more or less just a gesture. If someone really wanted to cheat, only an observant player would notice an extra 13 in the deck.
I guess what I am saying is, I agree with Mako: