They will never be completely flat, that's just not going to be possible also, you are ignoring the fact that manufacturers will often apply filtering (e.g. high frequency roll-off) to modify the output.
You really need to take off those barn door sized blinkers. You are entitled to have your own point of view but, you are not entitled to, effectively, assume that anyone who disagrees with you, is always wrong and therefore stupid.
You have an opinion, that's all it is. You have to learn to understand that not everyone will share your opinion and, that does not mean that they MUST be wrong.