These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Family-Unfriendly Aesop: Conformity and Commercialism are good. You know things are bad when even the movie itself points out how the tone would shift drastically if the Kranks were any other religion besides Catholic.
Unfortunate Implications: Giving yourself a break from a hideously expensive and time-consuming tradition (because your child won't be around to enjoy it) means you're selfish and heartless, so you must be set straight.
As several critics noted, you have to wonder what would happen if a Jewish family moved into this neighborhood.
One of the Christmas carolers actually asks if the family is Jewish. Apparently, in this universe, you're only allowed to avoid Christmas if you are Jewish.
Makes you wonder about other religions. Are they exempt?
Also noted is that the token black family also decides not to take part, yet no one seems to care.
What an Idiot: Both the crook that the cop picks up near the end of the movie, and the cop himself. The latter because, instead of driving him down to the station after he drops off Blair and her fiancee, decides to leave the man unattended in his car while he goes to the Kranks' party. The former because, even though he manages to escape the car with the help of a gullible kid, decides that instead of just counting his blessings and making a run for it, he'll just break into the house the policeman's in and steal some things.