Why I don't like Twitter, apart from the reasons outlined in TFA, is that it is nothing more than a less capable, centralized RSS.
With RSS, I can subscribe to pretty much any type of content: blogs, search-results, news, you name it (the list is almost endless). The major thing here is that I can subscribe to any type of content using an RSS-reader of my choice, and RSS providers can use any tooling they choose. With Twitter, the type of content I can subscribe to is incredibly limited, and both myself and the authors are tied into a specific vendor (to boot: Twitter).
So I'm completely at a loss as to what the big deal with Twitter is.
Here's how it works, and why it isn't already widely used.
The reason it's not widely used yet, and why it will not be widely used by individuals (a requirement for ENUM to become useful, IMHO), is because when registering an ENUM number costs EUR 45 signup fee + EUR 1.79/month, according to the website of one of the registrars that is currently contracted to sell ENUM numbers in the Netherlands.
It's a naive, domestic operating system without any breeding, but I think you'll be amused by its presumption.