A bit of perspective from someone with more than just a little bit of knowledge on this subject might be in order here.
As the article clearly states;
What's happening here is that S-Corps (Small Corporations) and LLC's (Limited Liability Corporations) are generally small businesses, which do make up the bulk of not only all businesses, but also employers, in the US, and as such generally don't have the cash flow to justify full Corporate status, so the owners simply claim all of the companies earnings (after 1099's, W-2's, Workers Comp and General Liability, employees matching Social Security, and other business related expenses) on their personal income tax returns, which are taxed at a HIGHER rate than Corporate taxes are.
I myself ran my business as an LLC the first few years I was in business for myself, simply because I was essentially a one man operation, and eventually had a couple of employees, until I got to the point where I was making enough to justify fully incorporating.
Where the article got it all wrong is in their assumption that they weren't paying Federal taxes, because they're paying at the higher "personal" rate, and LLC's don't pay "Corporate taxes", again since all of the money earned (after expenses) is the owners since he/she doesn't have a "CEO", "CFO", or any of the other things that full corporations have.
The other thing that they failed to mention is that many Corporations don't pay Corporate taxes when they have a "bad" year. Simply put, you don't pay taxes if you haven't made any money. The fact is that Ms. Kerr is playing the scare mongering card about the "evil corporations" again, and it's all a bunch of BS.