Web browsers let you hover over a link to query if it's clickable before clicking it.

Also in this case the problem is if a site has some text that's blue & clickable, and some text that's blue & not clickable. That's more or less what iOS 7 is doing. Colored text doesn't mean it performs an action. It might, it might not. Similarly, black text might be clickable, it might not. It might have a border, it might not. And these are all mixed together in the same app, or even a single screen such as the case of the alarm that the article is talking about.

Mousing over ever piece of text in a document to see if it's clickable isn't a great user experience. If you've ever tried using a site whose link style is 'non-underlined, blackish blue', you'll understand the problem, particularly if you suffer from colour blindness. The Guardian is a prime example of poor-usability when it comes to text links.

This doesn't seem like a very fair comparison. Most browsers account for this (by default) by using a different cursor symbol for linked text vs. non-linked text. Some also show the linked url in the browser UI also.

A web developer can override both those conventions and when they do, their links become less recognizable and their apps become less usable. Since there's no cursor on iOS touch screens, losing the visual cues is a similar problem.

[edit] You might argue that just tapping on something serves as the way to discover if a visual element is tappable on iOS. But it doesn't, as the original article states, it just makes the user wonder if something might be broken.

> Lots of link styles today have no text decoration but are rather just a different color, and are as easy as ever to use.

They're not, and their relative ease of use is only because users have learned over years that a few words looking markedly different (but not emphasized) might just be links.