Michael Tanner refers to the sentimentality of bad art as "merely the bank holiday of cynicism".
Speaking at greater length, Tomas Kulka of Tel Aviv University says this (from "Kitsch and Art"):
Kulka argues that kitsch is not bad art. He sees it as a unique aesthetic category, a special kind of art, characterized by three properties:
One: Kitsch depicts objects or themes that are highly charged with stock emotions. Kitsch is about simple feelings, universal ideas. Good and evil. Happy and sad. Your response to these ideas is automatic.
In fact, part of the appeal of kitsch seems to lie precisely in recognizing that as you look at it, you’re feeling the way you’re supposed to. Kitsch validates you.
Two: The objects or themes depicted by kitsch are instantly and effortlessly identifiable. Kitsch art is utterly conventional. There’s never any doubt about what it is you’re looking at. It’s a leprechaun, and only a leprechaun. It’s Santa Claus, and only Santa Claus. Kitsch art is surface art. It’s just what you expect.
Three (and most important): Kitsch does not substantially enrich our associations relating to the depicted objects or themes. The last thing kitsch wants to be is challenging. Pure kitsch is never ironic, ambiguous, troubling, or innovative.