I wouldn't want this to be codified into law, but why *can't* the teacher just allow kids to make up work? This doesn't sound like a "we no longer give out zeroes" policy so much as it is "we don't have set-in-stone deadlines except for, like, the end of the term or something." Boy oh boy, better than learn this now than the crushing truth that once they get to university they will... mostly be able to make up missed assignments or at least get partial credit for late ones.
As for the support the teacher is getting, it doesn't surprise me that there are a cadre of parents or non-parent citizens who think schools have gotten soft or something and we should be harder on kids than their teachers were hard on them.