It surely doesn't hurt anything lubing them IF done correctly. I just thought of another thing lubing them often screws up besides oiling the clutch plate: Drive shaft bolts coming loose. Very related when you think about it. I know from seeing many a worn airhead input spline that has been lubed regularly that lubing them does not save them from wear. I also know from tightening down literally hundreds of drive shaft bolts that if you tighten them down correctly, they don't come loose. Without a washer they need nothing but torqued down correctly and they never come loose. Loctite won't keep them from coming loose. Tightening them down will although I think some need to use loctite in order to remember to tighten things. It helps in that way for some. In the mean time 100RT and others out there, my experience has me betting your bike really needs something else worked on way more than those splines. Not always! But most of the time.
BTW, dry splines do not mean they need lubed. Most greases go dry there very quickly. That's the whole point of using moly. It is a dry lubricant.
Now before someone gets the itching to come after me personally for insisting there is only my way and no other way. Try reading what I wrote above again. I am here writing another post to get a message out that I rarely read on the net. Bond with your bike in a meaningful way. That way it matters. Harder to do yes I know but isn't that the way things most often work?
On tightening the drive shaft bolts: I highly suspect that if more people got a torque adapter and used a torque wrench to tighten down the drive shaft bolts they would probably just then realize just how tight those bolts are suppose to be. Those are tough threads and bolts!