I see it as two separate issues, that of militarizing regional waterways versus territorial ownership disputes. They are not synonymous; militarization being specific to the introduction of new interdictory weapon systems to a theater. So I do not equate what China is currently doing, territorial expansion/development (however one prefers to term it) with militarization.It is worth mentioning that Japan fortifying their islands is not quite the same as what China is doing, because those islands of Japan are considered their territory and not currently embroiled in a territorial dispute, whereas the reclaimed islands that China has built are part of a larger territorial dispute.
That said, the reasoning behind potential militarization of any degree, by any nation, in any theater in the world, is all the same -- that is, it depends on the perceived security environment.
That said, I do fully expect China will continue on the same path of regional militarization as that of Japan and the US per the circular logic and reasoning I noted in my earlier post. Something will need to change in the equation for this to be altered; perhaps a government level change within one or more of the countries with improved person-person contacts and negotiation prospects as a result. Difficult to say.