I found this whole thing to be highly amusing, and I think you will too.
We are at SIL's house (she normally hosts) doing the present-opening thing. The family does the one-person-opens-a-gift-at-a-time thing.
BIL, who flies in from across the country, gets a picture of the item he has been given. Item has been shipped to his home as 1) it violates TSA rules and cannot go in carry on luggage) and 2) it's kind of heavy. He has to complain about this.
Husband opens a gift from me, a new high speed card for his camera. Has to *** and moan about this.
SIL opens a Celine Dion CD (she likes Celine Dion and doesn't have this CD), and proceeds to crab about it. At this point, I start laughing and say something like "Why are you all complaining so much about gifts?" God's honest truth, SIL looks at me and says "Well, what are you supposed to say when you open a present?" I say "THANK YOU." Her husband, who is sitting a little ways from me, mutters under his breath "That phrase isn't in her vocabulary."
Later that evening I tell my husband that this is his family's version of Festivus--instead of "the airing of grievances" we get "complaining about presents." He laughed and said it's always been that way; that his mother was always critical of anything given to her, and it just rubbed off on all the kids. To them, that's normal behavior.