They actually did the most sensible thing possible. They set a target efficiency, and let the manufacturers figure out which technology to use in order to meet those requirements. The alternative would have been to make a specific energy-efficient technology mandatory, which would have unfairly benefited manufacturers focusing on that specific technology, and would have made the law outdated when a better technology inevitably comes along.

Nobody forced CFLs on people. They were simply the best option at that time, until LED bulbs improved.