Part 3
The practice of reserving the Eucharist is ancient, but the place of reservation was a cupboard in the sacristy, and the purpose of the reservation was to have the Eucharist available to take to the sick and dying. It absolutely did non occur to anyone in those early days to expose the Eucharist for adoration. It was meant to be eaten and drunk.

In the fifty years before V2, the ancient practice of regular communion was revived. People were slow to adopt this revised Eucharistic theology. The V2 liturgical revisions had many objectives, but one of these was to accelerate this return to the understanding of the Eucharist PRIMARILY as sacred food; and as part of that process, the altar became once again a table, a direct symbolic replacement for the dinner table at the Last Supper, and with it the tabernacle got displaced in various ways in different churches. 

It took 50 years to re-institute regular communion; it will take longer to re-conceive why we reserve the Eucharist.