That's a statement that's not as true as it used to be. Objective-C 2.0 introduced garbage collection, There are many novice programmers that are now jumping to ObjC because of the iPhone SDK hoopla.
Garbage collection is also available to code that executes at the pure C layer as well. I'd stand by my previous statement, and add that most of what ObjC brings to the table is some framework design patterns that you do have to learn, but that can be learned in far less than a week.