It is undemocratic and it doesn't deal with the real problem. The real problem is the public are too disengaged with what is going on in their government and don't enough about what they are up to, to hold them accountable at the ballot box. The end result will not be an improvement.
What it will do is entrench the problems even further. Because if we do get someone who is good and who can make real change he won't be there long enough to upset the apple cart. We will be even more disengaged because we will constantly be getting new people who we don't know their history. There is a saying, better the devil you know than the devil you don't know. We won't know anybody except the ones who are about to go.
Think about this. When they reach their limit and are no longer able to seek re-election what motivation do they have to do what the voters want? The most dangerous person is someone who has nothing to lose.
Also there is the issue that there are some projects that take years to move from initiation to completion. ie some crucial weapons systems like stealth have taken over 20 years to complete. Without some people who were there at the beginning of the project and understand it from the beginning you are gong to have people who have less understanding of project making key decisions on whether or not to continue. Without any experts on the subject good projects could be cancelled and bad ones could be continued.
Although there are some problems with career politicians, to replace them with a system of amateurs who are constantly being set back to the beginning of the learning curve could give us worse results than we already have.
So it's a bad idea that is a poor way to excuse voters from doing their homework, knowing what their representatives are up to and holding them accountable at the ballot box. It is saying we need a lottery system to pick our government because the people are too stupid to choose wisely.