Why a President requires no special qualification?
Every field requires expertise, be it software, engineering, law, medicine. On the other hand anyone can become a president if he has enough votes. And he can perform very poorly and yet nobody would fire him. Why isn't there any sort of test that evaluates whether a candidate is able to run a country.
Answers & Comments
Verified answer
I agree. But I'd doubt that a complete idiot would nominate himself to be president. He/she would probably have knowledge of how the government works and stuff before they'd try becoming president.
Also, you can impeach a president if they are doing a poor job or something wrong.