First of all, it's biblical! 1 Cor. 11:1 - again, Paul says, "Be imitators of me, as I am of Christ." The ultimate objective of veneration is imitation.
Second of all, it's tradition. Throughout early Christianity, Christians customarily met in the places where the martyrs had died, to build churches in their honor, and venerate their relics.
Please show me from scripture where bodies were exhumed and put on display for 'veneration'.