I don't think you are correct here. I've shot brakes from JP, surefire, and SJC and they redirect the flash into your field of view. Shoot any of them at night.
Yep just look at a Battle Comp or SureFire brake as examples. They both have ports on the top that direct gas/flash right into your sight line. Its just really hard to see in the day time.
Picture time! Surefire brake on a cloudy day. The first one you can see the gas coming out of the top ports, the second one. . . well. . . flash EVERYWHERE!
6c07de51 - Copy by NiftyVT, on Flickr
7e0723cd - Copy by NiftyVT, on Flickr