Gove's mistake over prepositions and articles/determiners is in truth an issue of what's wrong with that kind of 'grammar': which is mostly a finicky, crazily detailed business of arbitrary names for bits of sentences.

In fact, his mistake is a reason why it's a mistake to be doing it. Only a tiny handful of people can remember all of it so most people will always get some of it wrong. In other words there's something wrong with the knowledge not with people trying to remember it.

Same thing happened to Gove's sidekick Gibb. He was asked by @Marthakearney to identify the difference between a conjunction and a preposition and he fluffed it - on air on the News. Of course he did because a) it's hard to remember and b) the distinction in that case was false.