I find it odd that they don't make it more obvious to non "Apple-obsessive-macrumors-readers". It seems like it takes quite a few days for the badge to come up on the settings app. My parents have no idea what it means and don't update until I do it for them.
I don't find it odd to not want your servers to have a complete meltdown, and Apple is in no race to beat adoption records on a third-party chart.
For those who are antsy like the lot of us here, you just tap software update in settings to invoke the check and get it sooner. Otherwise, I think an OS update rolling out to hundreds of millions of users over the course of a few days works just fine for those who don't read tech blogs.