There are only a couple of reasons why one is preferable to the other and they're about anonymity.
Information is currency, if there is no need for someone to know my last name, I don't give it. Not because I suspect everyone of a hidden agenda, but because it only takes ONE malicious person fishing for info to make a mess.
Pretty much the same with staff, it's not the individual that is important it is the job title, so many companies actually use the job title as email address. It also mitigates against people humanising their problems with your staff and nutcases building a personal grudge with an easily identifiable employee, or a competitor building a relationship and perhaps even making personal contact.
Similar issues along that vein, not something that would happen every day, but in a security conscious world and especially in a small country they need to be considered.