Knowledge for knowledge's sake is not a popular reason for valuing university, but - in any civilised country - it ought to be one.
Sadly, the utilitarian argument (which dominates the UK debate) which wants a degree to translate into a job risks devaluing subjects which are, inherently, non-vocational: history, Classics, English literature, etc. Universities exist to protect - as far as is possible - these kinds of subjects.
My esteem for Labour as a party which had historically valued education as a means to social mobility took a bashing when figures like Charles Clarke or Ed Balls ridiculed the value of, for instance, medieval history. This exposed their ugly, and frankly (given their own educations), privileged philistinism.
There is still a place for universities as centres of learning which foster and nurture knowledge of all kinds, particularly in the modern world of debased "knowledge": the internet is, on the one hand, a miraculous tool for the dissemination of information; on the other, it is also (and rightly so!) a largely "unpoliced" one - much of the information available on certain subjects is inaccurate, wrong, misguided, etc. (as my students find out to their peril when they quote www.weirdsite.com as a source for their essays...). Academics and universities need to adapt more quickly to the information revolution so that they can be part of this landscape in a more contributive and positive way.
Aside from the question of how society values and disseminates knowledge of all kinds, there is also a pressing socio-economic/cultural point of which everyone should remind themselves. It is highly likely, regardless of figures like Robinson, that the professional classes will continue to value (certain kinds of) university degrees for their children, their employees, and their colleagues. There is, therefore, a compelling argument to be made that social mobility, therefore, may still depend on one's access to quality tertiary education. Should we therefore encourage our children to aspire to these degrees? Damn right we should.
Of course, I am sympathetic to the argument which says that only the brightest and best should attend university (which might lead one to conclude that universities offering, for instance, Sports Sciences or Media Studies - the typical whipping boy of the degree world - should be closed down, etc.), but we need to be very, very careful about chiming in too readily with a point of view which seeks to narrow the opportunities for young people, rather than open them up, particularly if there is nothing else to take there place.
There is nothing wrong with arguing that some form of tertiary education should be available to 50%, if not more, of young people, so long as this argument is made with the right kind of resources and destinations for school leavers. Perhaps universities have not yet adapted enough to make the case for this yet (although, as someone earlier in the thread pointed out, employers have now, effectively, passed on certain aspects of "training" to universities, anyway).
Having an educated population is an advantage for the UK. If we are not careful, the university educated from other countries - in our globalised and mobile world - will fill our workplaces at the expense of our own children.
We have a responsibility as a nation to educate as highly as possible as many of our young people (or older people! I am all for mature students!) as possible.