Don't tell them what their job is and isn't. You have no idea.
~ @JonnehboiSwag
What is that supposed to mean? We all do have some idea what staff do. They protect the server, handle issues, and do other general help. It is their job to help. By becoming staff they signed up to help.
That being said, having griefers pop up everywhere could be something that staff couldn't handle by themselves.
On the other hand, what could griefers steal thats important? A wood plank here, a cobblestone piece there. They obviously can't steal from chests. Sure, it would be annoying to keep on replacing that one block that griefers steal, but does that really out-weigh the awesomeness of slime blocks?
But I also have another idea. Alright, we disable it the slimes block for now. But what happens if we go directly to the towny plugin makers and give a suggestion. If enough people gave the suggestion they might listen to us.
So all of us members from Meepcraft who feel that slime blocks really are cool and important, should go to the Towny plugin makers and suggest that they protect slimeblocks from altering others plots.
All you have to do is go to here and then click the New Issue button. Then type in the whole thing about slimeblocks not altering other people plots,etc,etc. And then post the issue.