So I logged in to ATT, checked the box to opt out, hit submit, and now the page refreshes with the box unchecked. I highly doubt that I was successful in opting out.
Unless you live in an area where there's an enormous mesh WiFi network with that covers the entire city and handles AP roaming without dropping a connection then WiFi is not an acceptable substitute to cellular.
Wifi is not and will never be an acceptable replacement for a mobile data connection. I'm not happy to be an AT&T customer, but at least they provide me with consistent service everywhere I go.
It depends on where you live. In Copenhagen, I find wifi serves my needs quite well. There is wifi on the buses, on the trains, at home, in the office, in bars, in restaurants, in cafes, in libraries, at any university branch...
I will admit this sometimes leaves me without internet for up to 10 minutes, but I have cultivated a stoic mindset that lets me survive those periods.
I opted out by refusing to ever do business with AT&T after a hellish few months trying to deal with them over an internet service debacle. Once it became clear that their strategy is to lie to their customers, and then make sure that the time cost for you to get customer service is so high that you give up, I was through with them. I've never dealt with such a dysfunctional, willfully incompetent company.
With so many wifi hotspots around I dont need ATT Smartphone at all. I use Google Nexus with ATT GoPrepaid without any data connectivity. If I never need on I just go to the nearest Starbucks. :D