> apart from performance in larger projects, having a .svn folder everywhere is my biggest gripe

Working copy has only one .svn directory at its root in up-to-date Subversion client versions. The mentioned problem was fixed in SVN 1.7 (released in 2011).

> I think git popularized versioning systems in the first place as many developers just didn't use them at all.

It was not git. GitHub, its marketing and PR popularized git and version control in general. I think that before GitHub main focus was on versioning source code (recall SCM, source control management system). But the focus switched to universal version control (code + all non code assets).