I finally got my inverted Christmas tree this year (late to the party again).
I learned of this a few years ago via something called the "internet", which informs that it is an old Eastern European tradition and may even be the origin of anti-Polish "Polack" jokes, namely that in the late-19th-century Americans would visit their newly-arrived Polish neighbors homes and note that the Christmas tree was upside down and realize there was a right way, a wrong way, and the Polish way. My family has had a similar response to mine.
But I find it attractive and it opens up so much space underneath for what Christmas is about: presents. I just wish I had gone bigger. I'm tempted to get a real tree next year and see if I can gin up some sort of watering mechanism. Maybe if I bored out the trunk and just filled it with water...
Though maybe I could use another type of tree just to piss folks off more. Imagine an upside-down bonsai tree kitted out in ornaments. Or a bare deciduous tree, painted black. Perhaps even an artificial, bare deciduous tree made from metal so I can put candles in it. Or electrify it to generate arcs and discharges! There are a lot of possibilities for messing with Christmas here.