Earlier quoted context omitted.
Also it is a tax credit.. meaning you only get the $7,500 if you actually owe at least $7,5000.. AFTER the standard deduction. Basically, anyone with under ~$100k annual income would not even receive the whole credit, if any at all.
"Tax credits are subtracted not from taxable income, but directly from a person’s tax liability; they therefore reduce taxes dollar for dollar. As a result, credits have the same value for everyone who can claim their full value." http://www.taxpolicycenter.org/briefing-book/whats-differenc...
So setting aside whether this is fair or unfair, people that owe more taxes clearly get a bigger benefit from the credit.