Yup! That...in itself....is amazing. Why they call their rites and observances something new is very strange. Like you said....most of mainstream Christianity observes things that were held in esteem by pagan sun worshipers long before the Exodus......and they call it new????? Did anyone say "Sunday"?
Well it is just plain human nature to want to draw a crowd and if it requires allowing diversity of beliefs to have the crowd that is what the majority has always done. It sure is interesting how many times Israel turn her back upon the Heavenly Father, and we are told there is nothing new under the sun, what has been will be again.