Edit: I forgot about Android, but Java was "popular" before that - in fact Android probably uses Java because Java was popular...
But really, Java is a fine language, not much worse than C++, and, as far as static typing goes, fairly OK. What bothers me most is the insane proliferation of bloated frameworks and tools that Java seems to generate around itself. In order to use several popular tools, you need Eclipse. It's not a bad IDE, but needing an IDE for even basic stuff like building a web app clearly is a symptom of something that went very wrong. Some wrong decisions are really hard to undo.
I only use Java SE and Apache Commons libraries, along with a very handful speciality libraries. Very little fuss. I like it.
Languages aren't used in a vacuum, and the economics of them involve positive network externalities and switching costs, so 'individually' needs some qualification.
Of course there was the hype, the hope to find more developers, the idea that there should be only one language in the company and so on. (All wrong, imo...)
Maybe all those factors could be combined into a single one, "popularity" :-)
Is something I wrote about it several years ago.
I think the popularity of objc is hindered more by the fact that people would be moving a step back, if they were using it for something besides what it's designed for (cocoa apps).
To claim that objective-c doesn't count as popular because anyone who chooses to write for iOS must use it whether they like it or not, is like saying that java doesn't count as popular because anyone who chooses to develop on an emterprise stack that a corporation has built on java must use it.
I still think it's popular.