I've seen articles like this before, and it always bothers me. As many problems as most theater chains have these days (and they do have many), this is not one that's going to help.
Now, I admit, I honestly have not encountered too many people on phones when I go to the movies. It does happen that a light will come on every once in a while at a screening, but it's usually so fleeting I don't even notice. I do go to an awful lot of morning shows that aren't very crowded, yes, but I go to plenty of more normal, crowded showtimes, and it's still not the biggest issue. But extended texts and the occasional ring, that drives me batty. You're in here for two hours, it will not kill you to shut the thing off and pipe down.
Tim League's got it right. And while the Drafthouse is a (sadly) tiny chain, it also seems to be doing it right, if only because it's the one batch of theaters that's posting crazy profits and expanding while all other theater chains are losing money.