why don't they make a stretch dog leash that has a built in pocket for the dog**** bags?

I realize that it's common courtesy, and probably a law that we pick up after our dogs, but I hate those damn bags. I don't know if it's the brand that I buy or they're all that way, but they are harder to get open than a bank vault. So I have to pre-open the bags so I don't have to fight with while I walk my dog and I carry them in my pocket.

Anyone else have an issue opening their bags??