If I were on a team of developers, and every new team member got a loaded Macbook Pro, and I were stuck with Ye Olde HP from 2007, I would feel pretty slighted. It's patently unfair that other devs would be seen as valuable enough to have excellent hardware, while I were consigned to the dregs. Even more so that he was expected to bring his own, rather than have tools provided by the employer, especially given that then were already doing that for every other one of his peers.

Of course, being an experienced developer, I know that the way to remedy that is not with complaints about fairness -- decision makers might not even have realized that was what I was using. Rather, pointing out the productivity benefits of having hardware similar to other devs usually seems to suffice. (Spec out a machine, propose it, etc.) It's not your machine, it's the company's, and it lets you be a more productive resource.