From a liability standpoint, NPD would be much less at risk producing brake pedals than selling the disc brake conversion components they offer, since a brake pedal has basically no moving parts to fail.
NPD "offers" kits using the existing pedal, so if they are better or worse than an aftermarket design, it does not matter. They dont manufacture the parts, so their risk is limited. They are not selling you a pedal, so they are off the hook for that as well. Of course, other components may fail, which NPD may or may not be liable for, depending if they had a hand in manufacturing it. I bet if somebody made the pedals, NPD would be happy to sell them all day long.
Let's not focus too much on NPD on this, the guy was just passing along what potential mfgs were telling him. It really could be any vendor.
Another thing to consider is that complate brake systems cost a LOT more than just a pedal, and I am sure a lot of people in the mfg business don't want to deal with the risk for a $90 part. They would be more willing to take risk for a $1000 system.
I also have no doubt that someone could make a far better pedal now than was designed 40 years ago, although I am not sure that is the point.
At some point somebody will probably start making the pedals. Probably when the stockers have dried up and gone away.
As far as lawsuits, you don't have to hear about them. They do exist. Usually it's just somebody looking for a settlement. A few years ago a lady in La Holla won a big settlement against Porsche for a broken brake pedal, and we all remember how much Audi had to pay to defend themselves just based on pedal placement, not even a failure.
Anyone looking into the pedal business will look at those cases and have to form a decision on their own. For a $90 part, it appears that most aren't willing to risk it.