Sorry but you completely misunderstood my argument. In this example you are not the customer of the hammer, as you're not the one buying the Bluetooth chips and SW/FW for them, but the phone/widget manufacturer is buying the hammer(chips) and he's responsible for using it correctly (FW and antenna design) to build a product where Bluetooth works well.

But like I said in the comment above, if the phone/widget manufacturer fucks up the Bluetooth implementation (misuses the hammer) because they cheap out and buy the cheapest no-name Bluetooth chips they can find on the market instead of buying from established companies, and then farm out the FW and antenna design to the cheapest sweatshop in Shenzhen, Bangalore or Eastern Europe since cost cutting and crunch in the consumer hardware industry is rampant and everything gets nickel and dimed to fractions of a cent while being rushed out the door to meet Christmas sales season or some other arbitrary product release deadline, then the phone/widget manufacturer who sold you the device is to blame for the rushed and buggy implementation, not Bluetooth itself.

So to conclude, if your bluetooth phone and watch are buggy, then blame their manufacturers for improper Bluetooth implementation and validation and ask for fixes/replacements/refunds, as a correct Bluetooth implementation is possible to do if you hire skilled engineers ($$$) and give them time to perform validation tests (more $$$), but instead, most of the widget manufacturers(including car companies) cheap out, like I said before, and cut dozens of corners to get their product out the door quickly and cheaply so they can skim more of the profits.

I hope it's clear now.

Source: Former FW engineer for Bluetooth widgets