I was just about to say this.
Shockwave / Flash / nearly every other application in the world tells you your software is old, and asks if you want to update it, and it will keep telling you this until you check the "don't tell me again" box. Which few people do. So instead they get irritated that it always pops up, and get used to clicking "no" because they didn't want to deal with it then, and don't want to deal with it now. A year passes, they get a virus through an old exploit, and they blame the software instead of their habits / their IT department's dogma (which is not always incorrect, but frequently problematic).
Chrome, on the other hand, keeps itself up-to-date in the background, at all times, and doesn't ask you to deal with it. It doesn't even inform you it's doing so, aside from a minuscule little up-arrow on the wrench that disappears on the next launch - no progress bars, no delay, no "restart now", no alerts, nothing. There's no question if someone's using version X or Y; they have the latest of their branch. Period. Or they'll get it in a day or two, and problem solved.
Transparent updates, especially when they're nigh-totally transparent, are in an entirely different world than "do you want to update yes/no/cancel". It's apples and granite, or oranges and wolverines - there's no comparison ("apples are sweeter than wolverines").