For most of this century, UOR has been the #1 park in Orlando for Halloween and Spring events (excepting St Patrick's at Raglan) ... and a distant third for Christmas. So they pumped up the Grinch content, built a shiny new parade that could run earlier in the season, put a mini F&W in CityWalk ... and remained the third Christmas park in Orlando.
Variety of reasons for this, but I think a big one has to be the people who love traditional Christmas are largely distinct from those who love Halloween, Mardi Gras and Universal IPs. Much like they did with NYE, at a certain point, offer the bare minimum and rely on the fact the parks will be filled with casual guests in late December even if you do very little.
(FTR, the 20+ year-old Blues Brothers Holiday Show is my favorite Christmas thing in any theme park. But I also get its aesthetic is far from Candlelight or Wonderous Night.)