The charge is brought by anti-intelllectuals, too many of them conservatives
The charge of hairsplitting has always been one of the weapons in the arsenal of the anti-intellectual. One root of anti-intellectualism is a churlish hatred of all refinement. Another is laziness. Just as there are slugs who will not stray from their couches without the aid of motorized transport, there are mental slugs who will not engage in what Hegel calls die Anstrengung des Begriffs, the exertion of the concept. Thinking is hard work. One has to be careful, one has to be precise; one has to carve the bird of reality at the joints. It is no surprise that people don't like thinking. It cuts against our slothful grain. But surely any serious thinking about any topic issues in the making of distinctions that to the untutored may seem strained and unnecessary.
Consider the question of when it is appropriate to praise a person.
Should we praise a person who has merely done his duty? Should we praise people who feed, clothe, house, and educate their children? Should wives praise their husbands for being faithful, as I once heard Dennis Prager recommend? Of course not. For this is what they ought to do. We ought not praise them for doing such things; we ought to condemn them for not doing them. Praise is due only those actions that are above and beyond the call of duty. Such actions are called supererogatory. So we have a distinction between the obligatory and the supererogatory. The former pertains to those actions that morally must be done or else left undone, while the latter to those actions that are morally non-obligatory but such that if they are done they bring moral credit upon their agents.
Is that hairsplitting? Obviously not. We are in the presence of a genuine distinction. One would have to quite obtuse not to discern it. Clarity in moral matters demands the making of this distinction, and plenty of others besides.
A second example. The phrase, 'the truth, the whole truth, and nothing but the truth,' will strike some as containing redundant verbiage. But there is no redundancy here since (i) one can tell the truth without telling the whole truth by leaving truths out, and (ii) one can tell the whole truth without telling nothing but the truth by adding some falsehoods in. The legal phrase is not hairsplitting, but the making of necessary distinctions. Necessary for what? Necessary for clarity of thought. Why is that a good thing? Because clarity of thought is required for ethical action and for prudent action.
So what is hairsplitting if its is supposed to be something objectionable? One idea is that it is to make distinctions that correspond to nothing real, distinctions that are merely verbal. The 'distinction' between a glow bug and a fire fly, for example, is merely verbal: there is no distinction in reality. A glow bug just is a firefly. Similarly there is no distinction in reality between a bottle's being half-full and being half-empty. The only possible difference is in the attitude of someone, a drunk perhaps, who is elated at the bottle's being half-full and depressed at its being half-empty. But that is a difference in the drunk and not in the bottle.
But this is not what people usually mean by the charge of hairsplitting. What they seem to mean is the drawing of distinctions that don't make a practical difference. But whether a distinction makes a practical difference depends on the context and on one's purposes. A chess player must know when the game is drawn. One way to draw a chess game is by three-fold repetition of position. But there is a distinction between a consecutive and a nonconsecutive three-fold repetition of position, a distinction many players do not appreciate. When it is explained to them, as it is here some react with hairsplitting!
The truth of the matter is that there are very few occasions on which the charge of hairsplitting is justly made. On almost all occasions, the accuser is simply advertising his inability to grasp a distinction that the subject-matter requires. He is parading before us his lack of culture and mental acuity and his churlish refusal to be instructed.
Too many conservatives are like this. The cure for a leftist is not an anti-intellectual conservative any more than the cure for a Nazi is a communist.