I have java ferns and they look like that, even though they have plenty of little "plantlets". I have had some of them for almost 2 years, and in spite of the browning they do very well.
Nature is unsightly alot to. I was looking out my back window this morning at some palm fronds that are brown and still on the tree and thought how unsightly they looked .It's natural in nature, it's natural in the tank.