No, it's a business decision. To get to study whatever they want, they have to stick around for 3 years. They're holding a bonus perk over their head for the first 3 years someone is working. Based on what I've read in this thread and also from the Mother Jones journalist [1], they have a terrible time keeping people in the organization, from programmers to warehouse associates, and everything between I assume.
I can see how that explains the 3-year service minimum, but I'm not sure how that explains the field-of-study restrictions. Once you're there for 3 years, why do they care which courses you enroll in?
I guess I'm still confused why that matters to Amazon, unless it's part of some world-bettering mission. Wouldn't it be logistically simpler to say employees can enroll in any course offered by the state community college system, and wash their hands of it past that? I mean, they're just offering a perk as part of a compensation package, it's not like they're supposed to be their employees' parents or career counselors.
[1] http://www.motherjones.com/politics/2012/02/mac-mcclelland-f...