First, his buildings are now a target for terrorists. This would concern him if he weren't a narcissist and only looking after his own interests.
Second, there is no transparency for the American people to know what deals are going on behind closed doors. It can not continue without 100% transparency. It is an open invitation for corruption of epic proportion.
The fact that Trump hasn't completely divested his assets just shows that he doesn't understand the importance of the office he is going to hold. I can't bring myself to believe that Trump isn't going to take advantage of being the President. He needs to do more to assure the American people that he isn't going to have any conflicts of interest.
Yes, Donald Trump should have divested his interests a long time ago because he has said on many occasions that he so many companies that he owns or controls. Given the legal complexities of divestiture, he should have allowed himself and his transition team more time to get the job done before his impending inauguration.
Yes Trump should have divested his interests a long time ago. There is no way to be an effective President or Vice President while holding enormous financial interests in private companies that stand to benefit from policies the President makes. It is a completely reasonable demand and it's good to see Congress doing something about it.
President-elect Trump was not expected to win the presidency; and no one is probably more surprised by his win than Trump. Therefore, Trump did not really have a reason to divest his business interests long before the election. Trump's lawyers and accountants are capable of drawing up plans to remove Trump from the business to avoid any conflicts of interests.