Why quarantine plants?

When I bought my plants I didn't quarantine them. I got them from the same store too. They are all fine. I found that plants that aren't potted tend to dissinagrate and fall apart though.
 
I think some people want to catch the snails first, but I know there are more reasons
 
Snails are one reason, disease another. Did you know ich can be carried into your tank on plants? If you QT the plants in a tank with no fish, the ich will die since it has no host. That is just one example I can think of off the top of my head.
 
That is it in a nutshell. If the plant tanks at the LFS are occupied with plants, fish, and snails (they are at the LFS I use), then QT is cheap insurance that you have not brought something in that you do nor want.
 
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