"Approved for Exams" make more sense when you take into account the history of the Ti family of calculators.

Why are they still able to sell what is effectively a 30 year old computer for as much or more today than when it came out? Because they managed to get the family informally standardized as "The calculator every teacher in America understands well enough to manage students who use it. Therefore pretty much everything else that could be as or more advanced is effect banned."

It was an amazing piece of kit when it first came out. No doubt you could make something 100x better and 10x cheaper today if someone really tried. But, they would fail commercially because you can't design-in 30 years of legacy in the US school system.