I have adopted that "accept people as they are" mentality too and for the most part, I'm pretty easy-going. There is a fine line to being "accepting" and to be "walked on" too so even though it's fine to just "accept" who he is, that doesn't mean you can't work to improve the dynamic between the two of you. That doesn't mean changing WHO he is but rather, working with WHO he is and making the situation more tolerable for the both of you. I spent 14 years trying to and hoping to change my first partner and it got me nowhere...now I'm with a loving man who I wholeheartedly accept as a person but we are constantly working on our relationship dynamics.
Anyways, my 2 cents worth...it's easier to just "let go" of how people react when they are not close to you but when you are in a household with someone and with them all the time, dynamics need to be worked on so both people are happy and an environment of mutual respect is fostered.