The thing is, Owl, it's not just about formal discrimination which is, and should be, illegal. It's more about intangible, gut reactions to things. Like it or not, probably quite a few prosective employers will (initially, in the early days when your DS is trying to break into the job market, at least) be a bit older and will be likely to make -even subconcious - judgements about a person on paper.
It's human nature. It happens. You can legislate for everything, but you can't control people's thoughts. I know that if I came across a CV for a Joey or an Alfie, I'd probably take them a little less seriously than someone with another name. It's not big and it's not clever, but it's how humans function. Joey and Alfie will already be on the back foot when applying for jobs because I've already made a tiny (probably incorrect) judgement about them.
I'm not saying that people will stick to their judgements and first impressions, regardless of the facts. They won't, unless they're a bit stupid. But first impressions - like it or not - are important. Why create a hurdle for your child where there doesn't really need to be one?
That's my thought process on the matter, anyway. :)