There’s no point in opening your statement with “Out of respect” as an indication that you deliberately decided not to pursue a certain course. If you say it, you signal that you don’t want to keep the fact from them that there is a reason for disrespect in your mind. So while it is less deceptive/secretive/closed and more sincere and open, it also implies disrespect and a closed mind, already considering its own standpoint final. The openness of this choice of words can come from a feeling of superiority, which itself can work as an insult.
It’s somewhat similiar to saying “I could call you names, but…” or “Some people might say that you…”.
As a sidenote: It also reminds me of the somewhat related issue of “No pun intended”. I love puns, so when people keep saying this, it would piss me off if they weren’t the ones dissing themselves by openly showing their fear of not appearing in the proper light. It basically means you want to suck up to an uptight crowd, but at the same time be fun. You want to have it both ways, all the benefits with none of the drawbacks, but you really gain none.
For further details on that matter I can simply refer to this very good essay, a favorite of mine because it covers the topic thoroughly: