All points programs go through periodic devaluation cycles. Since I started collecting points in the mid 00s all the programs that are still around today have gone through at least 2-3 major devaluations, each. That's why savvy travelers advise to "earn and burn" points on the regular rather than save them up like a retirement account. Points only ever lose value.

Points expiry is another risk in playing the points and miles game. I wrote about an "Oh, shit!" moment a few weeks ago when I thought I might be about to lose 750,000 AA miles. I wasn't; I still had 11 months to go. I had no plans to fly AA within that timeframe, though, so I sought a different way to earn points and renew my entire balance.