Already in #1 you are being slightly misleading when you mention the reasons people want to ban plastic bags. It isn't that they aren't at all recyclable but most recycling programs don't. Secondly, many people are lazy and/or busy so they won't take the extra time needed to properly recycle that kind of plastic. Thirdly, even if people are taking them to specific places to recycle, it doesn't change the fact that they are ending up as litter one way or another.
