Here is some information in a link I found.

Also: Frogs like to hide under them. I know they are part of a healthy forest system (certainly in the north east where I grew up) and probably add moisture to the ground. Insects probably thrive under them. There is lots I don't know about ferns!

Please remember that just because we see no apparent "value" does not mean there is none.

Here is a link that might be useful: Ferns as Ecological Indicators

didn't check out the link, but I bet it mentions the fact that often times an area that is overbrowsed by deer will have an abundance of ferns and little else in the understory...anything else edible, including young trees and the lower browse on older trees, will have been nibbled away.
Such a setting probably looks rather attractive to the untrained eye...ferns are so graceful and soothing in a cool shady forest. It's a sign of trouble, though, if everything else is missing...

I thought ferns are also parts of healthy ecosystems? In deep undisturbed forests there are ferns.

Also: Cover and shelter are very important elements of habitat, no?