Personally I think it's fair- a graduate tax, that is. You pay back something like 10-20% of "excess" income ("excess" being the income beyond which may be needed to live an extremely average life) on some threshold that, I would hope, gradually increases with inflation over time. Obviously it doesn't increase with inflation- but it should imho- other than that, there's no issue with such a system.
Don't want the graduate tax? Go via an alternative route, or pick a profession that doesn't need you to be a graduate.
The graduate tax concept ensures that you pay back for the degree you got- those who earn lots subsidise those who earn less, and so forth. Obviously loans won't be paid back in full in most cases- I'm £100k+ in debt already and will probably only pay back £20-30k after my 30 years are up, but I will pay back to the system by some amount, ensuring the taxpayer isn't 100% shafted by my choice of getting my BSc/MSc/PhD (the PhD next on the agenda.)
Now, to those complaining about losing an excessive amount of their income to this graduate tax- if you earn 30k, and the threshold is 27k, you only pay back an extra £300 a year to this tax. Only those who earn much more than you will pay much more on this tax, and frankly I don't see a problem with that.
The fact someone on the average salary can't life a comfortable life, get a nice house, and go on a vacation a year, frankly has nothing to do with graduate taxes. Don't get stuck in the ludicrous battle against a graduate tax (just another distraction that catches the weak-minded and detracts from the real problems facing this country.) Instead, you should fight for higher salaries, fairer taxation (see: the fact that you can loop sales through Northern Island, offshore tax havens which our government supports), and so forth.
All these people whining about student loans & graduate taxes should realize that our system is quite good for the average domestic student, and in reality provides a much cleaner safety net than most of the systems in Europe (which as far as I am aware, in many cases i.e. Portugal/Poland, put more of the onus on the parents to support the child, or require more effort on the childs part in part-time work/etc.) Start fighting for things that matter.
Now, obviously not perfect...
- Multiple kids, minimum loan amount? Hah, parents can't afford that. But then you shouldn't have had so many kids.
- Tuition can't cover moving away? Part-time work not paying enough? Minimum wage here is not a true living wage- but then again, is it anywhere? You could live at home, but in any case this isn't ideal.
- I expect there are more problems
But many of these issues are mirrored elsewhere (or worse elsewhere) so it's a moot point, really.