You can thank the EPA for that. Even though the active ingredient in the fast acting stuff, chlorpyrifos (Dursban, Lorsban), is proven safe EPA rules are requiring a reduction in all uses of pesticides. Since chlorpyrifos is widely used in agriculture they decided it was going to come off the homeowner market. Same thing is going to happen the opposite way with carbaryl (Sevin), agriculture is going to lose it but homeowners will still be able to buy it for garden sprays, flea collars, etc.
In a lot of ways this is good. When you use an insecticide the bugs that are resistant to it go on to reproduce passing on the resistant trait. The more widespread a certain chemical is used the faster this happens, pretty soon it doesn't work. Reducing the use of individual chemicals slows this down because there is a pool of insects that succumb to the insecticide to breed with the resistant ones. Resistance doesn't become widespread.