My main problem with the stylus is that it's so easy to lose; who wants to carry around a separate part with their device?

That said, imagine if styluses (styli?) were mass produced and available as ubiquitously and cheaply as pencils. Lose one? No problem, there's another one on the table over there.

In that case, I can see styluses catching on big time, and as noted in the article, their precision would give them huge inherent advantages over fingers.