Side 1: Living in Florida you don't see much snow. So why not celebrate and promote a party in the snow?
Side 2: I'm flying hours and spending hundreds on a flight to get out of snow... why would I care to see more of it badly replicated in Epcot?
The LTM promo is to get locals/AP holders in the parks in the parks since FP+ will make getting on any actual attractions they would like to ride a 2 hour ordeal. It is not to get snowbirds to plan a vacation for next week to see the extra special offerings.
Sidebar: There are plans to spread this to the DLR this fall if all goes well. Which it is not.