You argue that it is unfair on those who don't go to university to pay for those who do.
Well, a favourite canard of the Right can be used in reverse: that's the "politics of envy".
But there is a far more serious problem with your logic, which is very monetarist, narrow-minded and misses the big picture. An obsessive focus on money always renders people incapable of looking at things holistically.
Firstly, you're making the false assumption that only the student benefits from his university education. That's absolutely wrong. The non-student also benefits from it. For example, the non-student benefits from the services provided by a large host of graduates - in medicine, teaching, social work, engineering, architecture, journalism, arts, ... . But conservatives and libertarians focus on the self, not society as a whole, because their ideology is individualism (' everything is about *me* ').
I'm in good health, so I don't really use the NHS at all. Other public services I hardly use include: the police (I've almost never been a victim of crime), the roads (I do very little driving), the rail network, the fire brigade, counsellors, legal aid, prisons, etc. By your logic, I should be bleating about paying taxes to support all those services for others, not myself.
But I don't bleat like that because I take the holistic view. All those services are needed for a civilised society. My taxes are the subscription I pay for membership of a club called 'civilised society'.
You keep bleating about "over-taxing", but that is simply another irrelevance (in addition to Dean Joel's irrelevant speculations about humans colonising other planets).
Over-taxing and colonising other planets are interesting theoretical discussions, but irrelevant because no one is even proposing either in the foreseeable future.
Labour are simply proposing to raise taxes to put us less out of step with others; and even with Labour's proposed increases, we will still be taxed less than most of our competitors.
Tories like to invoke the Laffer curve to support their argument about 'over-taxing'. But the Laffer curve actually supports Labour's proposals because it shows that revenue increases as you raise taxes. (According to Laffer, revenue is only damaged beyond a critical high tax rate, but Labour are not proposing to go anywhere near that region of the curve.)