I have an iPhone and a Bose Bluetooth earpiece.
Pressing the earpiece button, I can only presume that this is what you are calling the "Bluetooth button" because the iPhone does not have a Bluetooth button, connects me to Siri.
From there I can get her to call anyone in my contacts list or direct her to dial a specific number.
If I press the same button twice, the iPhone will dial the last number dialed.
Bottom line, methinks your rant is misplaced.
My old LG , when pressing the Bluetooth button , would beep twice and you would state whom to call and the phone would dial who you said. Freaking remarkable. Now the Iphone , when the Bluetooth button is pressed just dials the last number dialed. Kind of limits the hands free ability, that is unless you just RECEIVE calls for Bluetooth use. Why can't APPLE just have an option to determining what happens when the Bluetooth button is pressed. It already senses the press. I guess apple is paying their programmers to much or too little to fix this issue or maybe apple is planning a "SPECIAL" headset that does accept voice commands. They did it with their proprietary cables and chargers. Jeez lets screw the customers some more their all sheep any way. Now I got to go buy an ANDROID ****ing sucks.