Because if your charging your phone you have to set it upside down or on its side. And due to the steep angle of the built in shelf, a plugged in, upside down phone doesnt sit very stable. And navigation is not as easy to read when the phone is on its side. For occasional use its fine but I practically live in my truck for work so I really need a stable location for my phone. Last, I have a 2014 which does not have Android or Apple Car play. So Im stuck with GM Intellilink which does not offer screen sharing. Im toying with the idea of upgrading this.