It would of course be nice to keep a headphone jack, but if the trade off is for water and dust resistance, I could live without it. I almost always use AirPods for the iPad now anyway, and keep a Lightning adapter with my Bose earbuds. Water and dust resistance will allow the iPads to be used in a lot of work and play scenarios.
I don't buy this excuse, my friend. If one's using an iPad in hazardous elements, one will likely have a strong, protective case for said environments. iPads are quite fragile devices.