Wouldn't that favour cronyism and enforce a barrier to entry to those who don't fall in line with the dictats of the ruling elite? Furthermore, it also creates a caste of professional politicians.
What we need is completely socialized education so that the population doesn't get so dumbed down that they vote the loudest, least professional people into office.
Those people had been unrepresented and taken for granted, and a major factor of their motivation in voting for Trump was to signal their anger to DC.
In the long run, it's beneficial to society that this group has gotten recognition and some of their issues are being addressed.
Career politicians tend to have a support structure that identifies their preferred base and caters to them. Simple majority voting would mean that our politics would be dominated by major population areas.
Neither of those things are so bad in the short run, but in the long run you would have significant groups who would never have their concerns and interests addressed.
That our system makes it possible for a minority to win over the majority at times is a real strength.