It's inconceivable that projects are expected to host old docs forever. Jesus, it's in the zip that you get if you download the Github snapshot anyway. It's literally 20 seconds of your time to have your own local copy.
There is a big difference between forever and switching it off as soon as you change versions. Most people were still using 1.4 when 2 came out so leaving the documentation up for a year or something would not have been difficult.
python & django both host old docs for all in-use versions seemingly forever. Nobody's complaining that they're polluting google, or campaigning for them to be taken down. So why are people reflexively resisting a reasonable request for bootstrap 2.0 docs to stay up? status quo bias!
All of the documentation for old Haskell packages on Hackage are hosted online and it does pollute Google's results. Google often links to outdated versions and you have to take a couple steps to find the current version.
