Most people might feel this notice isn't important, but it is, because it's the first real confirmation of our fears as Apple users. The fact is you bought an Apple router, then you went home, plugged it, and voila, all your Apple devices worked out of the box. Everything worked. And when there was any issue, it either autorepaired or was easily fixable with the airport app.
Then, someday you tried a third-party router because you thought Apple ones were too expensive. Configuration needed a laptop with an ethernet cable, then directing Explorer to the URL of the local network for accessing the router admin page. You set it up following the instructions, and of course, it failed. So you connected the laptop again, the ethernet cable again, and finally you were able to have it working after some hours searching the culprit setting.
