I know XTR Di2 has been out for a couple of years now and XT Di2 just landed recently but I still hardly see new bikes with Di2 and I've only seen a few out on the trail but they were upgrades by the rider.

Is it just because XTR was so pricey that it never caught on much and XT is too new, or is electronic shifting just not something people are interested in when it comes to mountain biking?

Perhaps I just haven't noticed it as much since I'm not constantly staring at other people's bikes when I'm on the trail as opposed to group rides on the road. It just seems weird that you don't see too many new bikes advertised with the option.