[zokier]

I don't think the problem are standardized test institutions; for example Collegeboard, who administer AP and SAT tests, allow wide range of calculators from five manufacturers. Sure, they might not be the only game in town, but afaik they are the most influential one.

I think the problem is far closer to the grassroots, down to individual teachers taking the easier well trodden road of TI monoculture for various reasons ranging from ignorance, busyness or fear.