They should be allowed to vote because their interests, in which case may be better funding for whatever deparment they work in, should be represented as much as they can be.
Also, the principle is at stake. Do you allow for universal voting or not? If you do, then there is no debate to be had because the principle is all important. Everyone who is a citizen gets to vote.
If not, and you break universal voting to be non-public officials voting where do you draw the line? Public officials, fine, they're the first to go. Then what? How about highschool dropouts because lets face it, they'll never be smart enough to make an informed decision. Fine, get them out of the way too. Then get rid of those who are unemployed because lets face it, they'll only vote for the people who give them more unemployment benefit. Fine, get rid of them too from the electoral process. So one by one you get rid of the easily undesirable groups... then the more not so undesirable but you can still scrap them, like students. Sure, why should students vote? All they'll vote for is whoever promises them goodies. etc.
Where do you draw the line? Well you draw it when you can't sell the rhetoric anymore.
No, we either stand on principle or we don't. You don't bend democracy to the whims of one group or another because it hurts all.