I am saying a large part of why some players don't pan out is chance, that is a fact in my opinion. That does not excuse immature behavior, such as not committing to learning a language (even though I have said before that I think the language issue is over-blown, it was/is one of many issues he has had and not the biggest). What I am saying is that a dedicated pro, as you put it, who puts in the work reduces the chance of not making it while an immature one increases the chance of not making it. Puljujarvi probably falls into the latter category (even though I may not think it is as clear cut as some other do), but I definitely do not believe that it is as easy as saying that if only Puljujarvi would have been able to speak English and had a different attitude he would have panned out as we all hoped.
Edit: Actually what I think about Pulju's behaviour in this matter is summed up pretty good by
@Fourier above.