Classic MacOS screen modes always tried to deliver square pixels, in contrast to IBM/PC-compatible screen modes where pixels were rectangular. Apple also tried to stick to a consistent 72dpi for a long time.
The monitor I had wasn't capable of 1024x768. I got that custom resolution using a manually defined modeline determined through experimentation. It wasn't a simple VESA style display setting like the later 15" monitor I got. A flat CRT was quite a sight.
OK, fair enough. I don't think that's one I saw, then.
I do recall netbooks with 1024×600 screens, which were a bit of a pain. E.g. in Ubuntu Netbook Edition, LibreOffice dialog boxes wouldn't fit on the screen -- they extended off the bottom. Meaning you couldn't reach the "OK" or "Cancel" buttons. >_<
Another fun exercise was configuring an old Dell PowerEdge server I had, connected to a very old mono VGA monitor. *Really* VGA: it maxed out at 640×480 -- but sitting on top of the server, it fit under my table and it didn't draw much power.
Every allegedly text-only server Linux distro I tried -- I remember Ubuntu Server & Debian, but probably more -- had an 800×600 graphical splash screen, which sent my monitor into conniptions so that I then couldn't complete the setup process.
This was a problem with Windows Server 2008, too. It assumed you had unaccelerated SVGA graphics and couldn't and wouldn't do actual VGA mode. I had to identify my motherboard GPU, find a Vista driver for it, install it, accept a compatibility warning, and then I could forcibly choose the monitor type and pick IBM PS/2 VGA. Then Windows believed me and displayed a 640×480 mode that my screen could show.