I have to admit I've been using friends to get away tickets this season, since I gave up my season ticket when I moved away. But I had 60 odd points on my ST so I'm not feeling much guilt.
Generally I don't think there is a much fairer way of doing it. One thing they could perhaps do is have a split points system, both an overall total and a 'recent' total say... for the last ~1-2 years. 2 different potential loyalty criteria for each away match. Having either one can get you a ticket. That rewards long term accumulation and recent proliferation.