No one is saying the Jets are perfect and pretending that anyone is saying that is making a strawman argument.
In any case, we want the team to be better, many of us are pretty happy with the forwards and goaltending but see the defence as an area of potential improvement. But many of us clearly don't think it's as dire as you seem to, and some of us are even hopeful that Benn--who doesn't really seem better than anyone who's playing right now--might offer an advantage given the Jets' coaching staff's aversion to putting two young players together (an aversion that makes me confident that Benn will not be 'blocking' Heinola or Samberg). That a sheltered Benn/Stanley pair might allow for a Morrissey/DeMelo pair that can play above the level they have been when paired with Poolman or Beaulieu--there's potential for real value for that mere sixth but we need to see it play out
In any case, I don't think Benn, a sixth, or even DeMelo are a hill to die on so you should probably settle down.