I'm glad this topic came up. The new iPhone is suppose to be water proof according to a new commercial I saw. Just hose it off when you're done!
But seriously. I do service work. I have a universal remote ($1300) that I can hook up to any controller by using clips on the terminal wires that I have stripped back. It takes a little prep on the initial set up, but once done it's done.
After I installed my first Rachio for a customer, I thought about this. If I didn't have a remote, I would have to carry my phone through the check up and/or repair. And it can get messy, but it most certainly will get wet. The touch screens go bonkers when they get wet.
I think the remote add-on is a good idea, especially for service techs. And DIYs. Maybe something on future Gen 3 models with a USB port. A plug and play after market remote that uses RF instead of WiFi. Remote communication is paramount on bigger properties.