We all don't have the same internet connections that Mountain View has.
Luckily, Chrome use differential updates. This means each update is a tiny binary patch. If you combine them all on your network, it's still a smaller update then one single IE update of 250MB deployed to each machines.
Make that a few kb. And last time I checked at my work, admin updates usually happen during work hours and affects people working in the "lab". Also, it's 1 250mb that is sometimes installed on each machine on the network, so way worse than a few kb.
This is what has given IE6 its long life in the corporate world. While this is a pragmatic decision, it can hurt badly in the long run as we all know.