The intention of copyright is to promote the creation of works. Rewarding authors is the means, not the end. In the case of LOTR, Tolkien didn't write it to provide licensing revenue to his grandchildren; he wrote LOTR because the creation of fantasy languages and histories was his passion and he could make some money from it. A much shorter copyright would have sufficed to inspire the creation of LOTR. Furthermore, the creation of movie adaptations would be helped by LOTR coming out of copyright, not hindered. Disney's empire was built on adaptations of out-of-copyright stories. Shorter copyright would in many ways encourage the creation of more works.

Trademarks clearly should have much longer protection periods than copyright. In fact, a business should be able to operate infinitely under the same legally protected name as long as they remain an active business in good standing and the haven't lost their brand name to a word in common usage.