I do not believe that is true.CBET-DT is omidirectional,
FCCdata.org shows CBET is directional and sends nowhere near maximum power in the direction of Metro Detroit.
I can pick up channel 9 and channel 32 with occasional dropouts if I put a high quality indoor antenna in a south facing window of my single story ranch. I don't have Detroit's skyscrapers sitting between my house and the southern Essex County tower farm (which is located several miles due east of the Wyandotte / Trenton area), so that perhaps helps to a degree. I also don't have any large commercial or industrial buildings right down the street to act as a signal blocker.
One thing that perhaps *does* hinder DTV reception in my neck of the woods is the fact there is quite a bit of RF floating in the air near me. Numerous FM & TV stations have TX sites within five miles of my house. That wouldn't be an issue in a place such as Shelby Twp., for example.