Different people like different headphone for their detectors, its the ones that work the best for them is what they want. I know I wouldn't like to get a new detector that comes with only waterproof headphone which I don't need as much as you don't use the wireless, so now it is up to the dealer that sold the new detector to you to either trade in the ones you don't like for the ones you do like. If Minelab were to add the headphone you wanted would mean so many different options and different prices, so you would have to order them with what you wanted and wait for it, maybe for weeks or months. I am sure no dealer would want want to stock different option as the inventory would be expensive which would be pass on to the customer, which we all want to lowest price detector and let those that want different type of headphone get what they want, not what Minelab would think would be what you like for the added cost.
Myself I wish they wouldn't include headphone that most will never use and keep the price lower and let us the owners buy what we want. Over the years I have yet to see a set of headphones that come with a detector last that long as the quality is not there.
Rick