When you think there are simple answers to big problems it's generally because you don't actually understand the problem.
How would you outlaw lobbyists? Setting aside the fact that it would be unconstitutional, do you think it should be illegal for you to air your grievances to elected officials? That seems to fly directly in the face of democracy. Or should it only be that businesses aren't allowed to lobby? What about a small business that is being unfairly impacted by regulations, or being run out of business by a large company abusing a loophole in the law? Seems like them not having a voice in government would be a path to oligopoly or monopoly. If that's ok, where's the line in which business is allowed to lobby, and how do you keep a large business from simply hiring a small business to lobby on their behalf?