It's true that the subjunctive is largely invisible in English, and not much used these days anyway. However, that's the case quite often in French too (the invisible thing, I mean) with many regular verbs. As a French teacher, I find myself advising pupils to use irregular verbs deliberately so that it 'shows' the examiner that they are using the subjunctive. However, I don't really see that the 'invisibility' of the subjunctive matters in one's own native language - you don't get points for using it ! The fact that the majority of verbs remain the same means that most people get it right most of the time! Mind you, I have had reports sent back to me for correcting because I had used the subjunctive and the person reading it thought it was a mistake!