Seems you might be more up to speed on this than I, why should a business where the profits represent the income of the owner
Because that's not how it works. In millions of small businesses
the owner takes a salary but generally does not touch the profits; the profits are retained in the business to pay for growth (R&D, product development, infrastructure, more employees, etc) - what is left after Uncle Sam takes his wack, anyway.
I posited an example in another thread, to illustrate why Joe Dirt, small business owner, ends up being in the "1%" personal income tax category.
Joe draws a salary of 100K. Business makes a net profit of $200K. Joe's personal income tax obligation is then based on gross income of $300K.
Imagine how much more of that 200K profit would have stayed in the company if only taxed at 15%.
The point appears to be moot though; the proposed 25% limit isn't going to have much effect at all.