It still hurts today, because Microsoft puts a space between your first and last name in your profile if you are using a local account but not for a domain account, which causes all kinds of weird issues if you ever have to use cmd.exe...
It's a design decision and a good one, at that. Forcing 1 million developers to handle spaces properly while they spend 1 billion hours developing their software is preferable to 1 billion regular users having to remember to not use space, a perfectly good separator, in their 1 billion billions hours of usage of said software.
Speculation, but I suspect that Microsoft explicitly put both user data and programs in paths with long filenames and spaces to help force software to support those things. That always seemed like a good thing to me, it's ridiculous that we still have software that breaks on paths with spaces.
These are called 8.3 filenames. They're a filesystem feature. They're still created by default in Windows 10 on NTFS, but can be disabled or stripped using `fsutil`.
