Even if this isn't true, why have there been no publicized efforts to even challenge the law?

Don't assume every word from their mouth is true, until proven by your due diligence.

True clown.

The beauty is if rents can keep up with expenses then PI remains constant and that is where the appreciation of increasing rents becomes a good thing.Sure overall costs can come in below 50% then that is a safety net.

Taking massive action, networking, finding where you can add value and then executing is what separates the true entrepreneurs from wantapreneurs. 

Is this true? 

I met all the qualifications in Section 121 itself, but this following bit from Publication 523 states that "ALL of the following [must be] true:"- You weren't using the space for business or rental property at the time you sold the property.Technically, no...

While I am surprised at that, I also think it is the proper way to view real estate.I always go back to my first vacation rental purchase as an example:  In 2005, I bought a beautiful, 2-acre creek-side cabin in Cosby (near Gatlinburg) for $240,000. 

Yes thats true that take out or refinancing out financing can be risky thats why you plan it ahead of time or in advance of actual need.

You don't know the first thing about true SEO.