strong guys will be strong everywhere, even in mainland or HK. weak dudes will be weak even though they enter the "top" programs.
In the stock market there is always over and under valuation of stocks, but we should believe the logic of market efficiency at least in the long run, and history placements data of those schools really told us some underlying facts.
Admittedly, it is easy to get academic success in a top 30 program. Otherwise, there is still hope once you try your super best.