One Youtube video has a pretty convincing origin story of the A380.
Apparently Airbus approached Boeing about a joint project, but Boeing's analysis showed point-to-point (787) made more sense, and Airbus got the opposite result.
Pride no doubt had a part in it, as the investment is staggering.
What hurt A380 development badly from a mfg. perspective was the wiring harness initially didn't fit, causing a delay of up to 2 years, so they had to re-design that. (This is common, and happened to one recent Boeing model too.) Also the first examples had a weight problem.
A380 $6.1B in additional costs due to project delays
http://calleam.com/WTPF/?p=4700
But the biggest issues were:
1) point-to-point won over spoke-and-hub
2) renovation of each airport so it would fit
3) no US carriers ordered any
4) operating cost of $29,000/hour, smaller planes are a quarter.
6) The A380 is not a cargo-design like the 747 - the A380 doesn't have a level floor from what I've heard.