That's very true actually. The rubber compounds are much softer than all seasons because snow tires are meant to operate at much lower temperatures, and many of the compounds have special bubbles or hollow fillers to increase surface area for snow traction. Not good for making tires last in the dry. Once the temp warms up, tire wear starts accelerating a lot too. The same treadblock characteristics I was talking about before also make the wear rate faster. Smaller, deformable chunks of rubber will always wear faster than bigger, more solid chunks of any given rubber compound. If you get really good snow tires, the wear will be horribly depressing on dry roads, especially at anything other than very cold temps. Oh, and the fuel economy is worse because of the rolling friction. If you get decent snow tires, you'll get maybe 2 winters out of them in normal use, and that's a stretch if you have much of a commute at all. They're pretty much worthless once the tread gets much wear, because then they don't have enough depth to hold snow well or have proper treadblock deformation. The positive side is that they keep your nice expensive summer tires from getting too much mileage per year, and keep your pretty wheels from getting damaged.

I have Dunlop Wintersport 3Ds for winter, and I got them for the opposite reason as you would normally. I sought out snow tires with the best dry traction. They're not ultimately as good in the snow as many of the crazy snow tires, but they have much better dry grip and treadwear because the compound isn't as soft and the treadblock design isn't as compromised. We get very frequent snow where I am in Colorado, but it doesn't stick around long so it is dry most of the time. A lot of people here have really nice snow tires, many have studded snow tires too, but if you've ever driven on those in the dry, they are scary. Super squirmy, horrible steering feel, and they have horrible dry grip in corners. I'm not really willing to risk that much dry performance (and safety) for the best snow traction possible, unless I start living in the mountains where the snow falls weekly in feet instead of inches.