It sounds like they treated you poorly, and I'm naturally inclined to side with people who would abandon the exposure that a set of TechEd talks would bring in

It sounds like they treated you poorly, and I'm naturally inclined to side with people who would abandon the exposure that a set of TechEd talks would bring in favor of not ignoring his wife, but... ...did you make your wife's inclusion part of the contract? To the folks you dealt with on site, it may have seemed that you were springing something unexpected on them at the last second. "Hey, my wife gets in free to take pictures or I walk." Yes, it should have been trivial for them to allow that, but is it possible you came off as a bully? I wouldn't have made the same decision as they did, but I can imagine a scenario when bringing up your wife in the 11th hour would have gotten my ire up a little.