I've been a librarian for over 20 years, and have just started my first tenure track job at an institution that grants librarians tenure. So my attitude at the moment (three months into it) is ... wait and see. It's hard to form an opinion without having some real knowledge of how both systems work, so I'm waiting to see how this tenure thing works for me. So far, so good. As far as my daily work life goes, being on the tenure track makes no difference at all. Here, tenure requirements for librarians do not involve publishing or research, so I'm not doing anything differently than I did at non-tenure granting libraries.
I will say that if granting us tenure could somehow keep people like Senior Prof from lumping librarians with Masters Degrees in with maintenance staff - bring it on. I know, I know, he's a troll, but still.... jerk.
Ahh..but it won't. Granting tenure to librarians will not change Senior Prof's opinion of what librarians do, nor will it change the opinions of many of real professors just like him. Librarians are often viewed as clerical staff, but having tenure isn't going to change anyone's opinion. I came to the conclusion long ago that "who cares?" I'm just going to do my job. If I do it well, eventually even the trolls come around and find respect for them.