Much of the objection stems from what is meant by "poll", "constructive" etc., which are the reasons behind the QQuestion being closed. Viewed from a particular point of view, I can see that this QQuestion, and others like it, look like polls. I would argue however, that such a wide interpretation of the term "poll" could apply to a range of Questions/Answers where you could Answer the QQuestion using packages or approaches A, B, C etc.
I don' see this QQuestion and similar ones as being polls, because they can interpreted as asking for statements of fact. What tools are available for development in R? That is a clear Qquestion, with clear Answersanswers. Yes, this QQuestion will garner more Answers thatthan a big standard Qquestion, but number of Answers in an of itself should not be a criterion for considering closing a Qquestion.
Could the question to hand have been improved to remove some of the more subjective elements and to focus the QQuestion? Yes, and myself and the other active members of the [r] tag community here could and should have been a bit more proactive in responding to the comments by the likes of Robert Harvey who pointed out the problem. Instead we my have got bogged down in the comment discussion. However, the QQuestion has been closed and so we can't address this now. Could the QQuestion be reopened to attempt to remove the more subjective elements?
As for the "constructive" element, I fully understand why we don't want flame wars and extended debates about whose language/editor etc is biggest. But it seems overly restrictive to assume that the more open-ended Qsquestions will descend to such depths and propagate unconstructive Answers and comments. By the very nature of people voting, commenting and defending the QQuestion, I feel we have demonstrated that the QQuestion is constructive and interesting and we've tried to outline in comments here why it is so. I feel we have answered the "constructive" part of the argument.
It does seem somewhat heavy-handed to close Qsquestions before they descend into argument/debate. In other areas, the SO site/community expect people to behave appropriately, leave comments when down-voting etc. And the sentiments expressed on Meta appear to be that the community doesn't want to micro-manage everything and dictate how people use the site in every respect. There is a bit of a disconnect between the way we expect people to use the site and the way moderation is performed with respect to the FAQ. Some might call it dogmatic at times.
What I would argue for would be to give posts the benefit of the doubt in such circumstances when moderating. Perhaps see how things pan out first before making a decision and deciding to close. Much like Robert Harvey's comment on the QQuestion. We were perhaps naive in not addressing the issues Robert raised, but that naivety was more than likely due to our collective failure to realise exactly why this question might be viewed as being overly subjective. I don't think we will make that mistake again.