What was the rationale in making pretenders un-Blessable?

[TheMenacer]

I think it'd be really nice to have pretenders auto cast divine blessing and fanaticism. It just feels like if you were random militia #273542 you'd be pretty jazzed up about your god strolling into battle alongside you. Plus it adds a little extra oomph to your main army, making the inevitable gigantic clashes between primary armies all the more epic.