One reason is that this site only seems to have listings for the "top companies." These companies are very hard to get a job and and tend to pay well, so the home listings are probably skewed to suit buyers that work at the elite companies and have more money to blow than a normal person.
I bet that if and when this site begins targeting the other 99% of companies, the listings for those will trend lower to reflect the average salaries.
I bet that if and when this site begins targeting the other 99% of companies, the listings for those will trend lower to reflect the average salaries.