Broadly speaking, the publishers already paid the devs who made the game, so even if its abysmal, they may as well eat whatever minimal costs are involved in distributing the game to try and get something back. (I'm prettysure its illegal to retroactively yank back wages, since that'd be an obvious slippery slope of doom)
As far as pushing it back, if they've already turned out absolute junk, it'd be illogical to keep paying them even more to presumably make even more junk (whether you be the publisher, shareholders, kickstarters or whatever else footing the bills)