In all of the bathrooms, there is a recessed light/exhaust fan combo installed. I assume, due to the combo feature, is the reason there is no cover over the light fixture. However, the same light/exhaust is also located inside the master shower - not in the damp area but, the actual wet area. Visualize yourself taking a shower and looking directly above you as your washing your hair, with water spraying and splashing everywhere, you look right up into the can of the light! So, out of precaution, we keep the switch off -ALL THE TIME! Is this safe and to code?
For the record, I have never liked lights (or fans) in the shower, because they are a maintenance nightmare. That being said I know of no restriction about putting one in a shower area unless you are able to touch it or it comes into contact with the spray of the shower. So I am assuming your fixture/fan is high enough to meet all jurisdictional codes.
My only question would be if this was installed during construction or was an add in by a previous owner. If it's the latter, you may want to check with local code enforcement to see if it should be removed. I like your idea of never using it.