Both algae and moss are aesthetic issues. I'm not sure cavers should really *want* to entirely sterilize the formations (especially if it is a wet cave), considering the geomicrobiologists have made a pretty good case that bacteria, and nanobacteria may indeed provide nucleation sites for future calcite formation. The algae, although unnatural, don't do much damage to the formations, the way moss can. And, one has to take into account what lives in the cave. I've been in one show cave (I will not name) where the salamander population is artificially high, because of the gnats and other tiny insects which live in the moss. Pink salamanders basking under tiny suns in green moss--what a photo op!! While on a strict basis, the salamander population should be smaller, on the other hand, they could be seen as a tourist attraction, allowing non-cavers to see some critters they otherwise wouldn't.
I guess it just depends what the cave management is up to.