Someone asked that very question to 1,600 people, and the results show that, well honestly, nobody cares what other people say.
When asked if they thought it was appropriate for stores to say “Merry Christmas” to shoppers, about 66% of the group said that it IS appropriate.
When asked if it’s appropriate for stores to say “Happy Holidays,” 61% of the group said yes, it is appropriate.
Long story short, no matter what the stores say to customers, whether in advertising or in-store, a majority of people just don’t care whether you say “Merry Christmas” or “Happy Holidays.” HOWEVER, a larger number of individuals found “Happy Holidays” less appropriate for a store to say, but only 15% of people surveyed. 8% of people surveyed said “Merry Christmas” is inappropriate.
Check out the rest of the study here, complete with graphs and more details on the research.