What I've done there is known as a "hurricane prune." Ignorant folks think it's better to trim off nearly everything since it will prevent them from breaking during storms, and to prolong the time until the next pruning cycle. In reality, it simply starves the plant of food, which is produced by the leaves. As Carl said, this leads to a thinning of the trunk, as well as excess flowering and seed production. Palms grow from the top center, with the older, outer leaves yellowing and eventually dying off. Best practice is to remove the older dead and dying fronds, leaving live fronds at the "9 o'clock and 3 o'clock" positions.