The problems with North American release are not Paradox' responisbility in that Paradox licensed it to Atari, who is responsible for marketing and distribution. So requesting Paradox to explain what happened will not achieve results.
My Theory as to what happened - a combination of several problems each compounding the other :
Chain retailers did not pre-order in large amounts, likely resulting in Atari having a small initial pressing of the game for North America.
There was a rush on online ordering in the period between Christmas and New Year, more than was expected by the publisher, creating a shortage that could not be quickly made up due to the intervention of two major holidays.
The rush in online orders forced Atari to reallocate quantities pressed so no one outlet would benefit at the expense of others, all would be relatively short.
The Biggest Problem A major winter storm in the center of the country (really from the Rockies to the Appalachians) has backlogged the shipping channels, adding to further delay of a day or two from publisher to retailer, so that even the initial less-than-expected quantites at the retailers did not arrive on time in many parts of the nation. Hence why so few people got the game on Tues or Weds. Never underestimate the power of the forces of nature on the conduct of merchant activity.
From what I can gather, the retail end of the game industry is alot like the retail end of the music industry (my profession). Street dates listed by retailers are based on the plans of the publisher/label and are subject to last minute change without notice, and on the ability to get the product to the retailer without delay. Sometimes even the best plans fail, but we should at least be happy that Atari is ensuring the game is getting enough copies to meet demand. Try having to explain to a DJ that the vinyl record which came out last week is no longer available because the label only made 1500 copies and are not going to press any more, ever. Considering we use a gaming format falling from commerical favor in a genre of gaming that is niche at best, we fans of Paradox games are actually quite lucky.
So the result is what we have, a short delay of a couple days to perhaps a week. Not a major delay really considering how small the market for this game (compared to your big-budget Playstation titles), and definitely not the kind of delays for which the blame that can be laid at the feet of Paradox. How many of us painfully recall the hell of Strategy First's cack-handed distribution for previous Paradox titles. Unfortunately in the age of hyper-materialism, if instant gratification can not be achieved, many feel completely betrayed.