Politicians can't refer to social programs as "welfare" because it carries a negative connotation, and people on Medicare, Medicaid, and Social Security will be uncomfortable with being grouped with those on SNAP. They also can't refer to them as "social programs" because it's three short letters away from "socialism."

The use of the word "entitlements" is a lot like how socially left-leaning people are now more commonly referred to as "progressives" rather than "liberals."