Being a historian of early Christian, my first reaction to this is well, what is new? This is the exact conversation (with the same complaints) that the early Christians and the early Jews were having in the first and second centuries. Most Christians in this period celebrated Passover as a Christian holiday altering all the symbols so that they pointed to Christ. Our earliest homily is by Melito and it is the homily he preached at Passover. It has this classic reinterpretation, which also ends up being very anti-semitic in its orientation as you might well imagine. Easter isn't mentioned in any documents as far as I know until the fourth century (Nicaea, 325). When it is mentioned by Socrates Scholasticus (380), it is recognized as a local custom that was not biblical (that is Jesus and his apostles didn't command it) but had developed in the catholic churches as a way to celebrate the resurrection.
UPDATE: Link to Melito's sermon