It can be quite cheap to put in almost anything... But there is still a certain reluctance to do so...

First it is "another nickle." So unless there is a specific need for it, manufactures are still going to shave that nickle.

Second it takes software to process the data... again shaving that nickle.

And last even if the chip is in there, some phone service providers want to nickle and dime you for that feature... your nickle of course.