There's no need to have such a defensive reaction. There's plenty of reasons a result like this could appear, and most of them don't rely on "high-quality developers prefer vim/emacs".
As a tangential example, back when OSX market share started climbing a ~decade ago, it was a safe bet to say that the average OS X user was savvier than the average Windows user. This was true at a baseline regardless of what you think the "savvy" choice for an OS is: the simple fact that the sample of Windows users includes the large chunk of the population that didn't give any thought to their choice of computer (a sub-population that naturally is less savvy). This dynamic would hold true whether you think that savvy users would prefer Windows or OS X: by dint of being the default, the Windows-using population had its average savviness dragged down, a fact that has no bearing on the suitability of the OS for computer-literate users.
There could easily be a similar dynamic at play here: beginner developers are going to be more likely to be on a big GUI IDE, which would drag down the measured average quality of Eclipse users. This is entirely consistent with high-quality developers preferring Eclipse to Vim, or being split 50/50 between the two, etc etc. As you point out, confounders like age and experience are also likely contributors.
> It is possible that developers who code with vim and emacs are forced to focus on low-level details like method names while developers using IDE's can focus on getting stuff done.
FWIW, using Vim doesn't mean using raw Vim with no plugins. I used vim my entire time at Google and I was the most productive dev on most teams I was on. I'm pretty sure this would've been impossible without plugins at least including auto-complete, jumping to definitions, etc.