AwK - Honestly, you'd be surprised how much you can fit in one of the normal reuseable bags. Especially since you don't have the worry about the handle breaking. Try it sometime, maybe you'll realize it isn't that big a deal.
austintexas - You are choosing the less-harmful, and biodegradable, product and recycling it. Great. Add a few reuseable bags in there sometimes for when you shop at non-grocery stores and you're doing great. I'm not angry at you or anyone like you.
Reusing a non-biodegradable plastic bag one time before you throw it out (read: pooper scooper) isn't really don't anyone any good now, is it? I agree, it's easy...but is that how you determine how you do everything? I know for many the answer is yes, but perhaps that's worth a look.
I'm angry about this issue in particular because it is so easy and cheap (sometimes free!) to make a change and make a difference. Why people don't do it is beyond me.
And if you want to go another step, you should stop putting every piece of produce in plastic as well. You're going to wash everything before you eat it, right? So where's the harm in letting your fruits and veggies touch eachother in your canvas grocery bag? If it's something that is going to get everything wet and potentially damage something (read: lettuce), that's one thing. Bagging 6 apples is absurd.
It's easy to make a difference. And to be more cliche, be a part of the solution, not a part of the problem.