Previously, we decided Suggest X questions aren't good for the site, but we didn't do anything about it. We've been especially tolerant lately of "Suggest an Icon" questions, and we've had a lot of them.

It may be a good thing, because the site gets more activity and more content. But it may be a bad thing, because these questions aren't interesting to experts, and the mission of Stack Exchange is to make it easy for people to find quality information without weeding through a lot of noise. (I've written before about the balance between quality and quantity.)

We now have a good question about how to go about selecting an icon which is aligned with Stack Exchange's mission, I think it's time to close the "icon for X" questions and explicitly discourage them in the FAQ.