As the company's only technical hire, there's an expectation that he would be exceptional regardless of his age. There's also a question of how much he has to offer to the founders, and how much the founders have to offer him.

If these two biz dev guys can make the company successful no matter what the quality of the product, then he's not very valuable. If that's not true, though, then his work has a very direct impact on the value of the company, which generally means that he would have equity. The former case seems unlikely, so it seems like he's getting a raw deal.