In regards to the protests themselves then I'm sure most of the students were there to voice their dissaproval of the increase in fees. Perhaps some of them were deluded enough to think it would make a difference. Not since the Poll Tax riots has it made a difference in this country and even then the bigger influence was probably the fact that virtually everyone was against it (98-99% in opinion polls). The only real way to effect change in the modern political landscape is to enter into dialogue with a positive and credible alternative to the proposals being put forward.
I do have a small amount of sympathy for students in regards to their having to pay for someones profligacy, especially as until they were 18 they had no say in who was governing them. However, they do seem to forget that the rest of us have had to pay far more in increased taxes the past 13years to partly shore up that same profligate spending. In the end life isn't fair, nor will it ever be... learn to accept that and move on.