I have seen several (around a few dozen) on the 1910 census who were listed as confederate veterans. A very small percentage of all Confederates in the 1910 census.
I see little reason to argue the point. SOME did serve. There are other issues that deserve more attention. Most who want to wage "war" (verbal) over the issue are those who do little actual research, but are rather "armchair" historians who get caught up in the minutia (I know I spelled that wrong?). Perhaps transcribing records, tabulating or helping with graves registration would get focus off the little things and on more broad aspects of the war.