Well, not much of a theory - the facts line up pretty straight.
Take a look at earlier ones covered here.
Now, GMail goes offline. And Gears installer runs smack dab into... inability to cope with a proxy that requires authentication.
Almighty Google can't make its programmers create a dialog box that asks for proxy username and password? 407 Proxy Authentication Required is too complicated?
There were others before - Google Pack, Chrome. The feature's been requested, most probably more than once. It is trivial to implement (and please clue me in on certain security changes in Microsoft Windows that make it so difficult).
The stench is becoming tangible.