Then the electronic dimmer was invented, which work by turning the light bulb on and off faster than we can see it, 120 times a second. It is not 100% efficient, which is why dimming your lights 25% reduces your electricity consumption only 20%. And it is no wonder why it causes problems for compact fluorescents, which are not designed for this additional turning on and off of a switch 120 times per second.
A more efficient way to vary lighting conditions is to have different circuits; in our house we have two switches in the dining room, one for the central focus on the table and another for the perimeter of the room.
Conclusion: Dimmers are wasteful for any kind of bulb, so it is hard to be critical of CFLs for not dimming well, neither do incandescents. More info on dimmers from ::How Stuff Works