Every cable over 10 meters failed to pass 1080p, even at 8-bit, though Monster claims their m1000 Series can do just about anything (they didn't provide a cable over 10m to test and they don't sell it at lengths above 25 feet). At 10 meters the Monster Cable 700HD and 1000HD passes 8-bit, and we added Blue Jeans Cable (30 feet actually) and DVIGear. Blue Jeans, incidentally, uses a Belden-made HDMI cable. When we increased the bits to simulate 1080p at 12-bit Deep Color (similar to what's available in most HDMI 1.3a-rated products today) most manufacturers had to drop back to 5 meters to pass the signal. Blue Jeans passed it at 30 feet, but DVIGear requires their active cable solution to do a full 10 meters. Monster Cables' 1000HD cable also passed 1080p at 12-bit with no issues.

It turns out that manufacturers aren't idiots; and I bet more than a few realize that they can spec their cables higher due to the lack of content to prove them wrong. In short, they are getting away with it... for now.