I'm not sure why someone would want the incandescents but they did.
Cost? Just over 15 years ago, we moved into our new home I had spent a very happy 18 months building. Lighting was a mixture of 12 v QH sealed spots, 240 v linear QH, regular 240 v incandescents, and bi-pin 12 V QH.
Half of the conventional 240 v incandescents and all but one of the bi-pin QH have lasted the distance. The replacements for the conventional incandescents have been CFL and have all needed to be replaced several times. They are not as bright, take longer to turn on as well as having a much shorter life. And they cost several times a much to purchase. The first three were north of $AU20 each and the incandescents they replaced cost less than $AU2.00 each.
The sealed spots last from a few weeks to a year at most. The linear halogens last from a few weeks to about 18 months. The transformers for the 12 v globes have a lifespan of about two years.
Last year, I replaced three sealed spots with the brightest LED units I could find. Not only were they much dimmer than the 50W globes they replaced, it took only three weeks for the first one to fail. They cost several times as much. Worse, this bank of three globes lights one of the kitchen worksurfaces where I use very sharp knives and I need more light now for my ageing eyes, not less.
It's a bit hard to see any cost saving when units need constant replacement and those units cost so much more than what they replaced. It's a bit hard to see any energy saving given that the globes and the transformers require energy to manufacture. The cost of the transformers alone likely exceeds the cost in electricity saving; nearly a hundred so far at ~$AU10 purchased locally.
I have been told that the CFLs would last much longer if we left them constantly turned on rather than turning them off when we don't need the light. Also we should purchase a very expensive power conditioner to reduce the swings, sags and spikes in voltage. Our electricity supplier is only required to provide an average voltage of 240 v over a 24 hour period. Several neighbours have installed solar PV in recent years "to save money"* and made the voltage issue much worse: 210 to 260 volts.
I expect to be accused of wearing a tinfoil hat, but it seems to me that the move to make conventional incandescents illegal has more to do with increased revenue for GE, Philips, Sanyo etc than "saving the consumer money and the planet".
* After receiving a quote from a solar PV supplier I questioned their numbers as their claimed cost saving would require the units to supply 140% of their rated output. The supplier either couldn't, or wouldn't respond. My cost estimate was close to that of Choice, Australia's consumer magazine. My estimate of time to payback was 18 years and Choice's was 16 years; different supplier, and presumably different state. There's a reasonable chance of my being dead by then. It's also possible I'll be incapable of finding anything of interest to spend the consequent fairly trivial savings on if I survive.