Who else uses Objective C in any significant amount? It’s pretty much Apple.
The point is also that with iOS you don’t have a choice BUT to use Objective C. You can’t use alternates.
Devs want freedom. That’s one of the reasons they’re voting for Android as the long-term viable OS to support.
BUT... your information is inaccurate again, as usual. iPhone apps can be written in Objective-C, Javascript, C++ and plain old C languages. Apple is now accepting apps developed with Adobe's iPhone compiler. The C64 app has a BASIC interpreter. At my shop, we also use some of those languages on the server side to support communications with iPhone client apps. PHP works especially well with iPhones in a client-server arrangement, in combination with other systems like Apache and MySQL, although we sometimes use the iPhone's built-in SQLite database system too.
Meanwhile, Google is getting sued by Oracle over their use of the Java language, which is owned by Oracle after their acquisition of Sun Microsystems. No one can predict how that will turn out.