Since this is so far just a rumor, it may not yet be time, and the iPhone 7 might have the same headphone jack as before.
However:
Every time Apple makes a change (such as making the optical drive an optional accessory), there is a group of people who think it is no big deal because they don't use the old technology that much anyway, and there is another group of people whose workflows depend desperately on keeping the old technology in place indefinitely.
Perhaps you were in the first group for the optical drive. But it doesn't follow that being in the second group for the 3.5mm jack means Apple is making a mistake.
Those who needed the optical drive to be permanently inside their mac (and included in the price whether other people needed it or not) rather than hanging off the side were just as sure that Apple was dead wrong as those who feel that an optional adapter to make their old headset work with an iPhone is a totally unworkable solution.
This is true. But at the time of the optical drive I could already see my family and friends dependence on it very low. But now the dependence on the 3.5 mm jack is high amongst my friends and family. I'd consider most of them average consumers too. To be fair I could probably adjust to Bluetooth headphones with minimal fuss, I just don't really see what benefit we're gaining from losing it. When we lost the optical drive at least there was significant space savings.
If they want to lose the 3.5mm jack they need to proactively push Bluetooth headphones and push adoption. Maybe with the iPhone 7 they could include a 3.5mm jack, but put Bluetooth EarPods in the box. If they did this then people would probably start picking up the Bluetooth headphones and when the next iteration comes around there will be that many less people dependent on the 3.5mm jack.