I don't think it's so much about confidence, sure you feel more protected and perhaps gain confidence from wearing armour but in the end I want to wear it for different reasons. Mainly because I ride on my own. I value my knees, and I have a couple of young kids to look after at home so downtime would not be very nice.
If I wear it and never fall off well I guess I'll consider myself lucky. I still think it's worth having and using if you want to. Just like helmets never used to be mainstream and not everyone wore them if they had the option, perhaps armour is going the same way, becoming more widely acceptable as the standard, probably due to DH & FR influences in the sport.

I reckon there are probably alot of people, and new riders in particular who would like to wear some form of armour even in xc races, but in the end worry too much about what people thing and end up going with the main stream.

It's unfortunate that most of us have to have some kind of incident before thinking "what if" or "i wish i had armor" and then the pain is soon forgotten again.
From a womens perspective if pain wasn't forgotten I don't think anyone would be having more than one kid

I think I'll be deciding between the mace tectoninc, & race face FR.