I don't really think people are saying this. The point is that Tornadus doesn't really need to predict to beat its counters. It spams Hurricane, it U-Turns after you bring in a flying resist, it heals back to full health while your counter takes hazard damage (say, SR + 1 layer of Spikes), and you can bring in your flying resist counter (Dugtrio being the common one as it traps Jirachi and while it won't kill, it does enough to cripple Jirachi that it no longer threatens Tornadus / can switch in as effectively). Meanwhile, your counter has a 30% chance to be afflicted with confusion, thus creating the possibility that it will be unable to use its recovery move to heal on the U-Turn, which usually means Tornadus will win.
The most frustrating thing, is that it can do this over and over again, due to regenerator, and wear down its counters. Rotom-W for example, is stuck with Pain Split for recovery, which is unreliable and easy to exploit. It takes no skill whatsoever to abuse Tornadus, since its just "click Hurricane, then U-Turn out" rinse and repeat. Its safe, simple, and utterly, utterly risk free.