The "Not Constructive" close reason has a long and illustrious history.
In the early days of Stack Overflow, almost anything even remotely programming-related was on-topic. Then the Great Community Wiki wars began, and the creation of the "Not Programming Related" proposal on Area 51 (now known as Programmers.SE) was an attempt to preserve these very popular questions elsewhere so that the main site could stay "pure."
In short, this is not a new issue.
There are many problems with "Not Constructive" questions, and it has taken a long time just to understand them all. But I think it boils down to two distinct principles:
- Bikeshedding, and
- er...Bikeshedding.
BikesheddingBikeshedding occurs in the questions because, once you ask a question like "Tools for Professional R developers," you open the door for a nearly limitless supply of "Tools for Professional [your favorite technology] developers."
Bikeshedding occurs in the answers because, well, everyone has an opinion.
People like asking these kinds of questions because they are reputation magnets. There's nothing wrong with earning reputation, but reputation should be earned from concrete knowledge, not opinions; otherwise, it becomes a meaningless number. Reputation is supposed to be (more or less) a rough measure of your knowledge and your level of contribution to Stack Overflow, not your ability to solicit or provide opinions.
To put it another way, were the Wall Street Journal to operate on the principle of popularity, it would no longer be the Wall Street Journal; it would be the National Enquirer.
Ultimately, it's far less work for everyone if we just categorically disallow these kinds of questions.