One can argue that it’s tacky, or poorly timed given that Mr. Nimoy died this year. But don’t argue that it’s not (or anti) Christmas.
If a green tree can remind us of life in Christ, then other signs, natural and of human creative effort, can help tell the Gospel story. Jesus Christ is part of everything,
…for in him all things in heaven and on earth were created, things visible and invisible, whether thrones or dominions or rulers or powers—all things have been created through him and for him. He himself is before all things, and in him all things hold together. (Colossians 1:16-17 NRSV)
No, really. Jesus said that there’s no way to shut up creation’s testimony to him,
When he reached the place where the road started down the Mount of Olives, all of his followers began to shout and sing as they walked along, praising God for all the wonderful miracles they had seen.
“Blessings on the King who comes in the name of the Lord! Peace in heaven, and glory in highest heaven!”
But some of the Pharisees among the crowd said, “Teacher, rebuke your followers for saying things like that!”
He replied, “If they kept quiet, the stones along the road would burst into cheers!” (Luke 19:37-40)
What’s that have to do with the Spock ornament? Well, consider why Mr. Spock was dying under glass, as related in the article linked above,
In his final attack, the evil Khan activates the Genesis Device, an apocalyptic technological development designed to create habitable worlds for colonisation, after the total destruction of whatever existed before it detonates. The Starship Enterprise’s warp drive had been damaged in earlier battles in the film, so Spock faced fatal levels of radiation in order to access and repair the drive.
After Spock’s efforts, the Enterprise was able to escape the range of Genesis’ explosion in the nick of time, but Captain Kirk discovers Spock injured and rapidly deteriorating from the intense radiation poisoning taking over his body.
Spock explains that his decisions were purely logical (of course), and that his own sacrifice was necessary in order to save the rest of the crew.
Does that belong on a Christmas tree? Sure. Why was Jesus born?
Now since the children share in blood and flesh, he likewise shared in them, that through death he might destroy the one who has the power of death, that is, the devil, and free those who through fear of death had been subject to slavery all their life. (Hebrews 2:14-15 NAB)
Christmas was necessary. A sinless flesh and blood body came to be, was sacrificed to liberate our sinful bodies from slavery to the devil, and walked out of a tomb so that we, too might walk into eternal life.
And the whole creation, even a Star Trek ornament, carries that message for those “with ears to hear and eyes to see.”