A lot of the people I work with are worried about all the stuff that ends up in landfills. I applaud this concern - we should ALL be concerned about the amount of stuff that gets thrown away. I mention the plastic island to my children at least once a week as a means of shaming them into better buying habits, but that's another story.
Here are a few things I'd ask you to think about if you find you are frequently invoking The Landfill to excuse your hoarding tendencies.
1. Do you take things home that would otherwise be thrown away in order to "save them from the landfill"? I do hope not. Making your own pile of junk larger to keep from making a public pile of junk larger? Not okay. If your friend is about to throw away some perfectly good plastic cutlery and you're horrified at the idea of it landing at the city dump without ever having been used, you may take it to the thrift store. Period. Please do not take it home to sit in a dusty drawer. This is not helpful to you or to the planet. Your Unclutter Coach decrees that you may never use this excuse again. Better find another.
2. I hate to be the bearer of bad news, but eventually everything is going to end up in the landfill. It's just where things go when they are all used up. I'm a huge proponent of things getting loved and used until there's not an ounce of use left in them, but eventually it's all going to the dump. Please consider that by "saving" things from this fate, you are really just prolonging that journey. So if you think that the macrame pot holder is somehow being spared by its sojourn on your kitchen shelf, I have bad news for you. This might be a good time to practice acceptance.
I hate that our dumps and landfills are full of cheap crap that didn't last long enough to become a treasured part of anyone's household. But please, please, don't turn a dislike of cheap crap into a crusade to keep everything forever. The best thing you can do for our landfills is BUY LESS, buy better quality, reuse and recycle. Then say a little prayer of gratitude for the stuff that has served us and move on.