So many words.
2. Because the word "merry" is not a word that is really in common usage. No one says "Merry birthday" or "that sure was a merry party last night!" It just feels a bit twee, it doesn't trip easily off the tongue.
Feeling merry, lads?
3. Because we're not particularly bothered by the fact that some people celebrate Channukah or Ashura, or Saturnalia or even nothing.
4. TO DESTROY EVERYTHING YOU HOLD SACRED!!!! BWA-HA-HA-HA-HA-HA-HA-!!!!!!!