Airlines and Seatbelts

It seems that every time I ride on an airplane the pilot keeps the seat belt sign illuminated for practically the whole flight. It doesn't matter whether it's a 2 hour flight or 5 hour flight, the whole plane maybe gets 10 minutes to use the restroom. On a recent flight to California, the plane was in the air and had adjusted to it's flying altitude and more than several people got up to use the bathroom (I happened to be sitting next to the lavatories), they were told to return to their seat because the seat belt sign was still illuminated. One man ignored the flight attendant and used the restroom anyway. heehee
It didn't bother me so much when I didn't have kids, but when you have a poopy diaper or a toddler who needs to go NOW - what do you do? On Alaska Airlines I hit the call light and the flight attendant said to just be careful - which was nice but I don't think I would have gotten the same response from United.
There is evidence that long-haul flights (flight lasting four hours or more) may increase the risk of developing deep vein thrombosis (DVT). DVT is a condition where a blood clot forms in a deep vein, usually in the leg. DVT can cause pain and may lead to complications such as pulmonary embolism. The risk is mainly the result of prolonged immobility, which can happen during any form of long distance travel, whether by car, bus, train or air. I'm not too worried about developing DVT myself but there are people out there that do.
What about the crying baby. We've all been on the flight where the crying baby needs to be walked down the aisle to be soothed. It not only comforts the baby but the weary parents and the passengers who are tired of hearing it.
So come on airlines, cut us a break and give us more than 10 minutes of non-seat belt time. :)