As far as communicating in the hand in the Latin Rite, it was my understanding that the practice was actually an ancient one...the original method, in fact.
If so many organs come into contact with the Body of Christ, what is so terrible about skin contact, I wonder? Surely when he sojourned on the earth, people shook hands with the Lord or embraced him or otherwise touched His sacred body with their hands. I don't quite understand what the problem is.
I'm no expert, but I believe it has to do with self-communication. Ideally you're supposed to receive the Eucharist from someone above you in the hierarchy. You do receive it from a priest on the hand, but then you self-communicate. I think.
Didn't the Latin Church also used to specially bless four of the priest's fingers for the purpose of touching the Host? His other six unblessed fingers - and by extension all laymens' fingers - were not specially blessed. This makes some sense in the Latin theological idiom, I suppose.
Also, as far as ancient Eucharistic customs go, I read some churches used to hand out chunks of Eucharist for people to self-communicate during the week at home. (!!!) Maybe some extra sense of Eucharistic piety developed in the patristic age?
It could be one of those "genie out of the bottle" things. Once the custom is established that it is more reverent to do things one way, it's kind of hard to turn around and purposefully do them in a way that is now viewed as irreverent, without feeling a bit of that irreverent spirit yourself ... even if the act of its own nature was neutral.
Subjectively and aesthetically, it is more intimate to receive on the tongue. As a non-expert, it does seem more appropriate, also.