The points are not good forever. They have two sets of expiration; a "shelf life" and an inactivity period. So long as you shop (and use your card) at least once every 6 months, you do not have to worry about the inactivity. However, ALL points are subject to a rolling three-year shelf life. As long as you don't collect your points for more than three years without any use, it generally shouldn't be a problem. I work at corporate and have assisted in the loyalty program development a couple of years back so I'm very knowledgeable on the program.
Expiration is not a foreign concept nor do I feel that the Walgreens policy is unfair, so long as people are aware of the rules and monitor their own activity. Most programs have expiration (United, Hotels.com, etc.), some of which are very close to our rules and others are a little more flexible.