Fee discounts for full time PhD Students; is this discriminatory? In computer science many conferences provide a fee discount for graduate students. This is ok, but many times these discounts are limited to full time PhD students, and not available for part time ones.

Now, part time students many times are less lucky than full time ones, as often they don't have any scholarship, so ideally they have less resources than a full time student; so why these discounts are only for full time students? It would seem more natural the opposite..
This is not discriminatory. A large number of full-time PhD students, mostly among top-tier schools, sign a non-compete type of contract that ensures that they will not have a job while attempting their degree. So for conferences awarding discounts on a financial need basis, part-time PhD students who typically have the liberty to work if they wish, do not qualify for this financial assistance. Of course corner cases exist etc. , but in general, this is the mentality.