1. The power that sacerdotalism offers over the 'laity'.
2. The 'pull' of a long historical tradition that takes you back to within a few generations of the original Apostles. That's roughly how long it took for the truth to be subverted by religion, which replaced Jesus' gospel. Christianity is not unique in that respect. Exactly the same thing happened with the Jews, who turned the OT into a false religion. You want proof? Just read the NT - all of it - and note what the writers say about their persecutors, antagonists, etc.
3. Churches decorated with colourful icons. So much more interesting than our dull, spartan churches.
4. Closely linked to No.1, a theology that transfers responsibilty for your own salvation to someone else. On the day of judgement, I can say to God......'but your priest told me so........'
5. Following on from that, also a theology that allows me to ignore my true state before God, because I can now concentrate on the ritual, liturgy, sacraments, tradition, prayer to and worship of the saints, etc etc rather than address my need for a relationship with God thru His Son. It's very clever, enticing, appeals to the ego, but utterly inimical to a true understanding of the gospel message.