With the new AirPort Extreme and Airport Time Capsule, Apple isn't really at the vanguard of the router market. A year ago we already tested the first 802.11ac routers. It's of course no coincidence that the new routers are launched in conjunction with the new MacBook Air, which is compatible with 802.11ac.
Apple products tend to work the best with other Apple products, which is a very effective strategy for coaxing consumers into adopting the Apple eco-system. Apple routers tend to be purchased by people that already own other Apple products, even if it's just because of the AirPort protocol that's part of MacOS. For a long time it was the case with Apple routers that their WDS mode worked well only in combination with another Apple router. With the new Time Capsule it's clear that you will benefit if you own other Apple prodcuts. Making back-ups, for example, is a piece of cake thanks to Time Machine.