Does doggy involve a lack of respect?

Well, in my humble opinion, the men who state that and who believe in that statement tell more about themselves then about the reality.

To me, everything sexual you do with your partner, when consensual (these times you have to say that in addition, but when having sex with one another means that what you do is inherently consensual, and if it's not, then the partner who doesn't like what's happening should let the other partner know/feel), is done with the passion of that moment and is therefore not disrespectful at all. Simply because if it would be disrepectful, you can say that about any position. Respect for eachother is in your mind, feeling, touches, interaction ... it's felt in the whole act. Therefore, to answer the question, there is no lack of respect when you are going doggy.

Disrespect is an attitude, not a position. If both parties are enjoying it, then full speed ahead.

In my opinion "respect" is not matter of position. I like all kind of positions and what I like most is to give pleasure to my partner. As I told about "topless on the beach" often people talk about respect but they are just hipocrits. It is possible to make love "only" in missionary position and, at same time, have no respect at all. Disrespect is an attitude!