This disposable cast of victims is much more hapless than the last--so obviously doomed it's pointless to root for them as they struggle and scream toward their gory fates. (They don't have much of an opportunity to put up a fight, either.) As such, this Massacre rests entirely on the shoulders of its villains, and they can't bear the weight.
Measured doses of R. Lee Ermey's slimy, psychotic cornpone sheriff were what kept the first remake palatable; here his unctuous malice quickly reaches the saturation point and transmogrifies into campy comic relief. Leatherface is practically neutered as well, rationalized into irrelevance as an out-of-work butcher who went postal but has some (easily overcome) qualms about seeing other humans as meat. Seriously, these are our monsters? Drenching these characters in backstory to "humanize" them doesn't make them any scarier or more compelling--just silly and sad.
With the bad guys neutered and the good guys set up for a fall, this Massacre is just a list of obscenities and torture scenes scratched off a jumbled list, making it as limp and predictable as its predecessor was unnerving. If they can't bring any excitement to movies in which people are chased by a chainsaw-wielding maniac, someone should just--bbbzzzeeeooowwwrrr!--cut these guys off.