The crazy part about it is that most homeowners don't understand the problem.
I've spoken to a lot of people who have "regular" timers, and can't figure out why they don't work with CFL bulbs. Most of them end up leaving one incandescent bulb in the fixture, without knowing why (that's what someone else told them to do). They don't understand that that they need something to pass the current through the timer to make it work.
Some of the newer timers (produced in the past 5 years or so - maybe a bit longer) have a lithium battery in them, and that maintains the clock. The switching is done by either a solid-state switch, or a mechanical relay, powered by the battery. That's one way around the problem (it also helps make the timers more "power outage-proof", as they don't need to be reset, and will turn the lights back on if they should be on at the time the power comes back on).