FYI, you're wrong about half of that. Southwest points do expire without earning activity! (Ie, even redemption activity doesn't reset expiration.)

See here:
*Points will remain active as long as you have at least one qualifying earning activity every 24 months. Qualifying earning activities include: 1) completed travel on Southwest® qualifying flights, 2) points earned by transacting with any current Rapid Rewards® Partner, 3) points earned through everyday purchases using Southwest Airlines Rapid Rewards® Credit Cards and through points transferred from Diners Club®, and 4) points purchased for personal account use. Member should allow four to six weeks or such time as is otherwise specified for points to post from qualifying activity. Points gifted or transferred to another Member only keep the recipient’s point balance active. The last activity date will be the latter of the last qualifying earn activity or date of Award expiration.

(I don't claim to completely understand that last sentence, but since Standard Awards are going away in another month or so, you can presumably remove the last 5 words effectively.)