For what it's worth, it's a pretty small diagonal size. Netbooks used to be about this size, and those had exactly such low resolutions on them. Conversely, you'd see 1280x720, but especially 1366x786, more on regular variety laptops (~15"), and if you crunch the numbers for these (using standard ppi), it maps pretty much exactly right. So we've come a long way on Windows/Linux/BSD land, even if there's much more to go.

3840x2160@15.3" for example would be a nice even 3.0x display scale, at 287.96 PPI, and 128 PPD at 30° hfov to match the line pair resolving capability of the human eye [0] rather than the light dot resolving of 60 PPD, although of course still far from the 10x improvement over it via hyperacuity that you linked to earlier.

[0] https://en.wikipedia.org/wiki/Visual_acuity#Physiology