I have done the same, though I wasn't as happy with the telephone response as you seem to be. In my case, I missed a connection because of a half hour of ground idiocy at PHL following a four minute weather delay; all I really wanted was for someone to say "yeah, we screwed up on the ground; we'll try to learn from it."

Instead I got a form letter like the above; when I followed up, I got a phone call from someone who was very apologetic but took absolutely no responsibility for anything beyond following up on my complaint. When she did that, the response basically amounted to "Our computer says there was weather so we can't have done anything wrong."

Why US is incapable of saying "we screwed up" when they screw up is baffling to me.

The most galling thing is the bit about being "unable to offer compensation" -- it appears to be part of their form letter. I got that in mine -- and I hadn't asked for a cent. That they include it says, to me, that they view customer complaints as nothing more than a money grab. (And it underlines the cynicism to say 'unable' when everyone knows they mean 'unwilling.')