It's not necessarily the banning of the Blood from communion, but the process of intinction. In most RC churches nowadays, the Blood is communed via the chalice after one receives the Body.
Prior to the V2 reforms, the chalice was withheld from the faithful during communion time due to the perceived danger of spilling the Blood. While it sounds ridiculous to us who partake of the Holy Mysteries via the Holy Spoon, there had to have been a compelling reason some point in the past for such a restriction to have been placed.
Theologically, the Latins justify the apparent separation of the Body and Blood with the idea that after the consecration, both the Body and the Blood are fully Christ. Mystically speaking, the Body cannot be without the Blood and vice versa, so it is only necessary for the faithful to commune via the Body in order to receive Christ.