Yes exactly right. I believe it may be related to older non-retina displays. I'm on the Mac and Evernote looks perfectly fine on my MacBook Pro's retina screen. When I hook it up to my Apple Cinema Display, however, the issue reveals itself.
My external display may be older but it's a beautiful piece of hardware that I dropped over a g-note on some years ago. I've changed my MacBook multiple times but not my display and I'm sure as heck not about to throw it away because Evernote no longer supports it or because it's not the "latest and greatest". It's far more likely that I will throw Evernote away.
I also believe that this is a probably a very simple bug to fix because if you open Evernote in a new window on an old display the issue just corrects itself. Just render the text in the main window the exact same way you are doing in the new window!
What that says to me is that the only reason this is not getting fixed is because frankly it's just not a real concern to them. That customers like us make up a very negligible section of their customer base and they don't care if their product does not perform optimally for us. Whether or not that is true, it's certainly the impression they are giving.