In the past I worked at a mid level 4G provider in the US who had to deal with the larger providers on a regular basis. I was always astounded at how little they knew about their own networks.

Regarding the articles statement of providers wanting an "all-in-one" solution, I have seen that in person, where management forced it, found it was horrible and then gave in and let us build the mixed vendor solution that worked well. I've personally mixed enode-b's from 2 different vendors to 3 different vendors SGW's and a different vendors PGW with no issues.

The "One Throat To Choke" idea doesn't work if your business depends on that throat to operate so you end up with the vendor calling the shots instead of the business.