Regardless of whether it is a real problem or not, here’s my 0.02 Eur: I’ve spent the better part of a decade helping people get “standard” phones working on “standard” networks, and let me tell you, there are plenty of reasons why carriers do field testing, configuration checks, service integration and formal acceptance of handsets before adding them to their portfolio.
Sure, you can always go the unlocked route (and the radio environment is fundamentally different in Europe than in the US, since spectrum is used more uniformly), but when you buy a device from a carrier you don’t just get support for it - you also get something that went through inter-operability testing and service integration work and was proven to work on their network (which, incidentally, is one small part of what I help manage).