Halloween is tomorrow and those decorations have been displayed in stores since August. AUGUST! I shouldn't be seeing a scarecrow or pumpkins until September, when it is actually Fall.
Christmas, however, is on a whole 'nother league. The famous Grove in Los Angeles just put up their big tree to display and Target stores already have everything from Santa to fake snow for your Christmas needs. I love Christmas, but not when it's October. Let me wear my cat ears first before I put on the Santa hat, please.
The marketing strategy for these displays comes from the idea that "it's never to early to celebrate a joyous holiday". Last year, consumers thought stores were putting up decorations too early because it completely made people not enjoy Thanksgiving. It turned into "let's have this turkey and ham dinner that Mom slaved over and buy Christmas presents on Black Friday". Keep in mind, stores also had their Black Friday sales on Thanksgiving day.
The time of giving and joy is no longer present (pun intended) because the holiday turned into it's own marketing campaign for you to spend your money and time at department stores.