I've noticed the same trend in my short time on GIS Stack Exchange. Finding some of the information in the documentation of some commercial and open source products can be extremely difficult or require a specialized skill set. So in some sense, asking questions that are difficult to find in the documentation may be reasonable.
To be fair, it's not just Esri users, but they seem to be the most common at the moment.
If we introduce any kind of "general reference" reason for closing, it would be more useful to require those voting to closing it to provide a link to the general reference (and a Google search link may not be sufficient since the results will change over time). If a link to the doc can't easily be found, maybe it shouldn't be closed.
Where the answer is basically "RTFM", I've been trying to provide the link to the documentation rather than example code. The problem is this may be creating a dependency where some users will ask others to RTFM on their behalf.
Also, I think the correct term for this particular phenomena would not be "RTFM", but rather "LTRTFM".