In a sense I agree. I will say Merry Christmas on the 24 & 25 of December, similarly I will say Happy Chanukah during the eight days of Chanukah, Happy New Year on December 31 & January 1 Happy St.Nicholas day on December6, Happy Winter Solstice on the 21-22 Devcember etc. Otherwise between Thanksgiving & My Birthday (9 Jan) I say Happy holidays.
I don't have a problem with using "Happy Holidays", or anything really. I wouldn't even be offended by someone wishing me a "Happy Chanukah".
I think its wrong to say that wishing someone a "Merry Christmas" is offensive and/or is pushing your religion on them.