Not every instance of using the words "what about" is an instance of "whataboutism"---as fun as it must be for these people to have a mindless counter they can use any time they hear a certain set of words. Whataboutism refers specifically to the use of long standing historical grievances to justify present violence: It has its origins in the "troubles" Ireland faced. If people condemned the IRA, IRA proponents would say "what about Bloody Sunday?" to justify their cause. It does not refer to showing that a country is applying a standard that it itself could not pass. If one could never point out hypocrisy on the world stage, then any country could condemn any other country at any time without concern for whether the standards they are applying are at all realistic.
If Russia says "we are invading because of all those neo-Nazis" in Ukraine, and I say "what about the fact that you have even more such neo-Nazi groups in Russia" that is not whataboutism even though I did say the words "what about": That is saying that the principle you are using to justify your invasion of Ukraine would also justify another country invading you and, since you would not be in favor of toppling your own government, you cannot actively use it as a justification for toppling another. That is pointing out an inconsistency in Russia's philosophical position---not a pointless dredging up of an old historical grievance.
Now if I said "what about Stalin and the people he murdered" that would be whataboutism. Still, whataboutism is a little like "conspiracy theory." (MSM logic: Collusion theory good; conspiracy theory bad. Forget that they are synonyms.) It is a loosely defined concept---how far back in time does an accusation have to go for it to cease to be relevant?
It is also ironic to see Russophiles charging others with whataboutism, as all of Russian disputation is whataboutism: You guys won't be left with much rhetorical ammunition if you decide to ban whatabout type arguments. (Now, was my last point whataboutism?)
So, yes, I think it is relevant that Russia has its own neonazi problem and that Russia would never agree to seeing its own government toppled on account of their presence. Russia is applying a standard that she herself cannot meet. However, if—because this counterexample—deals with the accuser and that fact makes you think you are witnessing a tu quoque fallacy: I will give you another one.
Syria is Baathist. Baathism is rooted in Nazism, directly inspired by it. Yet Russia opposed the attempts to overthrow Assad; in fact, Russia is allied to Assad. How can Russia be allied with a regime inspired by Nazism directly, Baathism, while supposedly trying to overthrow a “neonaza” government whose nazism consists of having a small neonazi contingent in its national guard? Of course, the answer is that Putin has other motives.