In terms of the A321, AA is almost done with the standardization to 176(NEO) or 170(non-NEO) coach seats. Delta A321 is 172(non NEO) and 174(NEO). Both airlines have 20F on that aircraft. I didn't check UA, but I'm pretty sure they're in line. So, I'm not sure if AA is leading the industry in worst legroom. IFE - well, I'm in the 'who cares' camp. It's a nice to have, but it wouldn't sway me to jump ship to another airline just because they have it.
More seats is about more revenue. And with ticket prices at what they are (and fuel prices), the airlines won't back off of this.