What purpose would there be to not use frosted?
If they want something besides just plain ol' boring frosted, you can print to most of them, I do it all the time. I do it for medical facilities, banks, restaurants, doors, windows, glass partitions... It's a whole market in itself.
I've done color fades & shades, striping, images, logos, restrooms, scrolls, silhouettes, there are also several different frosted vinyl styles (etched, frosted, dusted, crystal, etc), you can even print/ cut it for specialty decals on glass. The possibilities of what you can do are endless to easily fit a customer's needs, without having to try to resort to replicating the frosted part of it.