Whether you think grain is important/relevant/desirable is not to be confused with how large or visible it is. Of course some people may not take many pics with sky or other smooth grey tones in, but it does not change the effect that Rodinal has on grain, only how visible it is in your photos.
I am amazed that you can get comparable grain from Rodinal (all things being equal) compared to D76. This does not square at all with my findings.
I am not a grain hater at all, just pointing out as inaccurate the assertion that Rodinal is not a fairly grainy developer. It is, but if you start with a film that is incredibly fine grained, it should be fairly obvious that the grain will still remain relatively small... even if relatively larger than with many other developers. If you shoot subjects that naturally hide grain or enlarge them relatively little, then once again it matters not. If you want grain, then so much the better.
I often add Rodinal to Xtol to increase grain and bite. Its contribution is immediately obvious and tends to result in negs somewhere between rodinal and Xtol alone. This can be very handy, giving you two extremes and some in between.
None of my comments were related to the important/desirability of grain, only the effect that Rodinal has on it compared to other developers.