I don’t buy complete bikes because I like what I like and not many bikes come with the combos I want.
With regards to the spare hanger thing, my Banshee frame came with one. And some big stickers!
I’m a big fan of Sram gears because I like the clunk. It also means much easier to set up and doesn’t get too affected by mud and cable stretch. I ripped a bike with the latest XT stuff on it and the shifting action was too light for me. My old X0 on the BFe has a lovely clunky, definitive action.
I can’t really comment on Avid brakes because I’ve never had them, but I do remember when they could do no wrong. I like Shimano brakes so will keep using them.
I also like my Fox forks. I’ve had three pairs of coil ones and they’ve all been faultless. I’d much rather them than RS which I just don’t like the feel of (and I’ve never forgiven them for the Pyslo).
I can see how internally routed cables would be a pain, but have never had a bike with them.