Please note: this is entirely my personal opinion
I've been following the disharmony over the CILIP rebrand since all members were invited to complete a questionnaire which included ranking 6 possible names for the professional body as part of the rebranding. I didn't like any of the names and, while I don't dispute the need for a rebrand, I question the necessity of changing the name as part of it.
The reason for changing the name seems to be simply that no one knows who CILIP is and it is difficult/boring to explain...that bothers me a lot. There are so many societies/charities/bodies with initials that need to be explained at first. I'm sure when the NSPCC first started asking for donations they had to constantly expand "we're the National Society for the Prevention of Cruelty to Children" - not a catchy name but encompasses exactly what they do and now everyone recognises it. The IEEE is probably unknown to most of you but it is the professional body for my husband's line of work - 'The Institute for Electrical and Electronic Engineers' - but they're not considering changing it just because the layman doesn't recognise it immediately. So it is a question of whether it is more important to be known by the wider public or to be the respected professional body that, if you look into choosing that certain career, you will discover and value. I think in CILIP's case it is hard to separate the two ideas because of the vast range of industries or sectors that an 'information professional' might find themselves in, or that someone might drift into without realising that they're doing something that could be under the umbrella of CILIP.
The name does seem to be becoming more widely known, someone commented that the CILIP Carnegie Greenaway Awards were mentioned in the news without an explanation of what CILIP is on the assumption that people know (or don't care I suppose), so capitalise on that instead of starting from scratch. If people who work for CILIP are constantly having to explain what it is, to rolled eyeballs and boredom, that won't change with a snazzy new name. It will still require explanation, and the second you use the word 'library' or 'librarian' or 'Information Professional' they will look just as glazed as ever. What might change it is a better strapline, smarter logo, wider outreach and publicity and a firm idea of exactly what CILIP's purpose is. It isn't a union for library staff, although it should support it's members interests, but a source of professional development, support, and understanding as well as the mouth piece for the profession.
One thing I saw on twitter, that prompted me to write something, was the statement, quoted by someone listening to speakers at the emergency general meeting, "'Librarian' is known and understood: 'information professional' could be an IT worker". This made me laugh, because people might assume they know what a Librarian does but I think our working lives are generally pretty different to the stereotype of a librarian 'shh'ing patrons and sitting at a desk reading a book! But that is why I think CILIP is a good name for the body, Library and Information Professionals, because we don't all work in a physical library and we're not all called Librarians. If it is doing it's job right then less people will slowly side-step away from us at parties and might actually be interested in what we do.
So that is why I think rebranding is important - and to be fair this is probably the cheapest rebrand since the concept of 'rebranding' began - but please don't change the name. I for one am quite happy explaining what CILIP is but would be very embarrassed to be known as one of 'The Knowledge People'.