Here’s a suggestion: Let’s try to have one consistent standard. If you don’t want to hear Christians whining about being greeted with “happy holidays” or “season’s greetings,” then don’t whine about people greeting you with “Merry Christmas.”
Not because it’s the same — it’s not. There’s a big difference between being inclusive (e.g. “season” or “holidays”) and being exclusive (referring to one specific religion’s holiday, e.g. “Christmas”).
But the principle is, if someone’s trying to be nice, do you give them some credit for that, or do you sneer at their attempt just because it doesn’t measure up to your standards, or meet your preferences?
On the other hand, if you want to preserve the right to complain loudly and vociferously about being wished “Merry Christmas” (and you don’t mind that you’re playing into every negative stereotype about atheists being “strident” or “militant” or “politically correct” or whatever), then understand that other people have just as much right to complain, just as loudly and vociferously, about being wished “happy holidays” or whatever.
Sure, complaining about insufficient inclusivity isn’t the same as complaining about insufficient exclusivity, but free speech is free speech, even for people who are wrong or stupid or bigoted or whatever. So pick a standard, and stick with it.
(pic via Atheist Holiday Greeting Cards — collect them all!)