It really depends. If you're going to be flying with the same carrier/alliance from year-to-year, then it probably is. You can accumulate miles, althoguh you'll never be elite, and with miles from CC spend and other sources, you should easily be able to manage a reward ticket each year (or at least a one-way upgrade for your holidays).

Have a look at what CC programmes are available for your carriers, and see if you think its worth it. I'd say, probably it will be.