You can heel strike in bare feet too. Barefoot Rick (who has run 60+ barefoot marathons) heel strikes. I've run with him, and I've seen it. How he hasn't developed heel spurs, I have no idea.
I heel strike quite a bit still too, especially in KSOs and when doing speedwork. You get used to it just like you get used to the feel of forefoot striking. Doesn't hurt, but you can feel the impact shoot up your leg sometimes.
I don't do it a lot though because it's never been my natural gait. I just do it because I can. And I'm not entirely convinced that a little bit of heel strike with a high cadence and short strides is a horrible thing.