The domestic sitcom has gotten a shakeup in recent years by circumventing its white-bread tendencies with solid network shows like Black-ish and Fresh Off the Boat. But apart from these isolated isles of inventiveness, the genre’s in dire shape. The time couldn’t be riper for a skewering like the one offered by Santa Clarita Diet. Alas, Netflix’s 10-episode half-hour sitcom gets only a few stabs in before falling prey to the very conventions it’s trying to upset.