See the somewhat reliable wiki entry. I know Jews who put up trees. Go anywhere in world in December & in non-Christian cultures like Japan & you will see end-of-year trees. They are as much a symbol of commerce as anything else. That's why municipal trees in the US have survived challenges from the ACLU all these years - they are extra-religious symbols more widely associated with winter & the season of Jesus's birth than Christianity.Indeed, some fundamentalist Christians reject the practice, believing they are prohibited by scripture.
That being said, I think everybody should cut the Rabbi some slack. He made a mistake letting his lawyer go nuclear, has admitted it & apologized for it, the trees are back & no one was harmed. If we want to blame anybody for what happened at SEA-TAC, lets blame SCOTUS for making all of these issues such a lucrative business for self-aggrandizing lawyers & crooked hate-groups like the ACLU.
It's Yuletide/Christmas/Ramadan/Hannukah/Winter Solstice/End of Year Sale time: the season for giving and forgiving.
Could you point me to an exact quote from the Rabbi where he did what say here. All I have read is the typical democrat appology of pointing the finger at the other party and declaring yourself the victim and it was all a misunderstanding.