Actually, this is a pretty odd thing for the CITH people. If you make the “We sin more by our tongue than by our hands” argument, what’s the difference when your tongue will be touching the Host when you put It into your mouth anyway?
The obsession with touching the Host with our hands is easily explainable by the obsession with making our Faith an “experience” as much as possible. We have to “feel” everything. The Faith starts to be about the emotions instead othe intellect, and this mindset carries over into everything.
With CITH, receiving in the hand instead of the tongue is a way to “experience” God. It can make one worry more about the physical contact with God instead of the spiritual. When receiving on the tongue, the physical contact is minimized and it is a humbler manner of receiving (this is obvious - imagine that you have an atheist watching you go up for communion. If you receive standing in the hand and pop the Host into your mouth, I doubt he’d think of laughing at you. If you receive kneeling and allow the priest to place this “round piece of bread” on your tongue, I think the atheist would be more likely to laugh at you.)
There was a really good sermon I heard at mass two months ago or so…the priest was talking about the Resurrection of Christ and Mary Magdalene’s discovery of Christ. She reached out to touch Him, but he stopped her. Why? Mary loved Him very much, but now he was trying to perfect that love. He was trying to make her love more spiritual, rather than physical. We can easily see the parallel with CITH. It stresses the touching of Christ rather than the spiritual receiving of Christ into our souls.