As usual, you fail to address the question. But, I will still answer you.
Why should ANY president, or any member of his extended family, profit at all from business entities that Trump has not severed himself from?
That is easy. Because this is America, and they are free to do business. You have failed to identify profits made "because he is president". You are confusing BO's theory that "you didn't build that, government did", with the Clintons full life measure of profit from their governmental positions, to that of somebody that built his business in the private sector.
Lets take another shot at a coherent explanation from you.
WHY should Hunter Biden profit from his daddy's position as VP, while daddy brags about getting another countries AG fired over investigations into companies that are paying his boy millions?
“I said, ‘You’re not getting the billion.’ I’m going to be leaving here in, I think it was about six hours. I looked at them and said: ‘I’m leaving in six hours. If the prosecutor is not fired, you’re not getting the money,’” Biden recalled telling Poroshenko.
“Well, son of a bitch, he got fired. And they put in place someone who was solid at the time,” Biden told the Council on Foreign Relations event, insisting that President Obama was in on the threat.
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Shokin told me in written answers to questions that, before he was fired as general prosecutor, he had made “specific plans” for the investigation that “included interrogations and other crime-investigation procedures into all members of the executive board, including Hunter Biden.”
And, of course, why should Trump, alone among all presidents over the past 50 years, not reveal his income tax returns?
Being 35 years of age, and a natural born citizen are constitutional requirements. Releasing your tax return is not. Now if you want to change the constitution, then amend it. Don't try to usurp the constitution through partisan state voting interference.