Yes, that's true and is why I mentioned it! However it's not that common and, of course, the less you customise the less chance there is that something will stop displaying as you wanted it to!

It's possibly not that strange. If the 17" screen has a comparitively lower resolution (pixels-per-inch) the font-smoothing can become more noticeable and make the letters look at bit "greyer / blurry".

Looking into Joplin shows that the default editor text colour is #32373F which is noticably lighter than black and can then be made to look a bit lighter again by font-smoothing.

colours