Well, here is why I care so much.
By way of analogy....
Let's take one of the most holy and sacred days of your own religion...say, Yom Kippur.
Now imagine that it became customary among Jewish people to exchange gifts on Yom Kippur.
Next, imagine that merchants throughout the country, tried to lure you into their stores every year just before Yom Kippur. The whole reason for the malls and stores being decorated and the sales being offered just before Yom Kippur was because of Yom Kippur.
Then suppose that there was sort of an "unwritten rule" that said, Let's not mention Yom Kippur....let's instead celebrate a "Holiday".
Remembering that Yom Kippur is one of the most h ioly days in your religion, and then seeing that it became offensive -- not to try to make money off of Yom Kippur -- but for YOU to mention Yom Kippur, don't you think you might "care" about this whole notion that even wishing others a "Happy" (as in may you know the joy of God's forgiveness and may you experience the happiness that comes from bieng with your family) "Yom Kippur" is offensive?
That, in a nutshell, is why I "care so much" about this issue.
We don't wish each a other a "Happy Yom Kippur". And for holiday greetings, we usually say, "Chag Sameach" which means Happy Holiday. Unless it's Rosh Hashanah, then there is a longer greeting.