Honestly, 2.5 years is way too long to wait for a NIC driver. The actual amount of code that has to be written isn't that great, and open source Linux drivers could probably be used for reference.
I work at a company that does software development (though I'm not directly involved with development myself), and they regularly complete major development projects in a few hundred to a thousand hours, which when split between a few people means a few months max. If we spent years on a single development project, we'd be out of business.
Either the person responsible isn't dedicating enough time to development (less than a few hours per week), or simply doesn't have the skills and experience necessary for driver development.
For what it's worth, this is the explanation from a dev point of view, in case you did not read the entire original thread:
Jamie Krueger#6