I assume you can support that statement with facts?
Install the latest version of .net on your machine. First notice that the download is HUGE, then go to windows\microsoft.net\framework and notice there will be a folder for every “final” version (1.x, 2.x and 3.x) in there. .net supports previous versions by INCLUDING them, 1.1 code runs against 1.1, 3.5 supports it by including 1.1 in the install.