This may not have been the best drama ever produced, an understatement. But it does seem to have tried to as believably as possible show just how the British authorities excused themselves from pursuing the worst criminals this world has yet seen, in a stupid vainglorious attempt to claw back their faded imperial grandeur. We may sneer at the idea that this happened. It did. With the flesh still rotting on the murdered peoples corpses those in power in Britain waved away the smell and got on with business like nothing had happened.
So if this made some true blue Brits uncomfortable and compelled them to write angry hateful reviews, then it did its purpose as a piece of drama very well. So anyone who felt it necessary to jump online to write a tirade has been made to feel outrage by what they "claimed" to be poor work or "worthless" or "a waste of money". If it was why did it move you so? Why not just change the channel or go watch YouTube?