wait are you serious or is that just some sarcasm? You honestly think that if you buy an unlocked phone that its ok that you dont have LTE on it because that carrier is not an offical Apple partner? It's like you would buy a car and if you dont go to a certain gas station pump company your car would only go to 100km/h and no more. Seriously? No wonder Apple does these kind of stupid things if people like you think that this is completely normal.
Yeah, the "we need to test the networks first before we can enable LTE on them" excuse is just BS. I find it hard to believe that Apple is the only manufacturer who needs to test their phones on all european lte networks separately before they can approve it while every other manufacturer have no issues with those networks (and how can you actually test the performance/coverage properly if you can't even support all the necessary bands to begin with..). Even if there were some issues with the network, it's really not Apple's problem and if the customer still wants to use his/her phone on such network then it's their own problem. And really, if Apple would really care about customer's experience with 2g/3g/lte networks, they wouldn't have released the iPhone on any US operators in the first place