This is one of the issues that frustrates me most about librarianship as a profession, and, apparently, it frustrates many other people as well. (In fact, I recently had to unsubscribe to a mailing list I belonged to because it had become nothing but post after post about the unfairness of the professional vs. support staff division in libraries).

My problem is not with the MLS as a standard, but with the MLS as the only standard. In many subject and functional specialities, other experience such as work as an apprentice or other types of education such as a subject master’s/Ph.D are more relevant and useful than a MLS. And it seems strange to me that a person with a non-library science Ph.D would not be considered a professional while a person with only a MLS would.

Of course, maybe I am bitter, since I cannot have a business card, and I have to pay for professional memberships and conferences myself (particularly sad, since “non-professionals” make less money and do not get discounts). Or maybe I am just frustrated by all of the time and effort that the library profession had devoted to this issue and all of the ill will these distinctions have produced. After all, librarians definitely have more pressing issues to address.

In answer to your closing question, though, I do not think that holding a “non-professional” position will affect your career. It is the MLS that is the most important thing–or so it seems. [Hopping down from my soap box now :)]