I understand your point of view. Here's my insight on this.

French is my mother tongue, and I was quite good at it a few years ago. I thought that people misusing words or making blatant grammar errors were careless and demonstrated an absence of perfectionism. Then I started to work and study in English. Since then, my level of English has greatly improved, but my mastery of French syntax and grammar intricacies is decreasing. In fact, I noticed that I tend to forget much of the edge cases of French. Sometime I write a text in French and get to feel bad while re-reading it, knowing I used to have a much better style and grammar.

Of course, I could dedicate a greater part of my time to nurturing my study of both languages details. But natural languages intricacies are too often irrationals, or too far stretching for the added value they bring. Thus I have a hard time finding the passion to go in their details, master them and use them. I don't mean I won't investigate them when I first encounter them; I will out of curiosity, but I won't give them as much importance.

Now, I got to start learning a third language, which is fundamentally different from French and English: Vietnamese. As I study it, I find further less reasons to concentrate on each languages edge cases. I understand the beauty of using a language to its full extent. But I do not intend to be a master of any specific language, I intend on communicating ideas in the three languages. I prefer being a master at communicating using languages, than being a master at communicating in one language. As long as I am able to communicate any idea of any complexity, I'll be fine.

Maybe it's a sad use of the Art of Languages, using only their generic components. But I feel my brain can only hold this much by-hearth-illogical-details, and there are only so few minutes left in my life, I have to make good use of each one.

So now, my perspective on language comes to be that my ability to communicate with 90% correctness with as many people as possible is more important than my ability to be correct 100% of the time in a single language.

It's quite similar to my view on programming languages. They come and they go: concentrating on a single one, learning and exploiting its intricacies seems inefficient to the bigger picture, and more error prone when working with other people who might not understand my use of little known features. Knowing to effectively convey meaning in many languages seems more useful. Not that I wish to be "jack-of-all trades, master of none"; just that I think I can be a master at languages, without being master of a language.

So to sum it up, I used to think mastery of a language was a symbol of perfectionism. Then I got to feel that only so many details about a language are useful in 99% of the cases. Then my recent experience at learning a third language further comforted this opinion. And when I look back at my friends who write perfect French but have little energy left to learn other languages, I feel sorry for them as they are putting themselves in cages.

Thus, I think one can have an easy time programming even though they do not master the intricacies of a single natural language. =)