"Ontario has recently moved toward more detailed and ongoing parent-teacher communication, but it’s in addition to traditional grades."

Lol.  Some teachers dint get the memo I guess.  Out of my sons five teachers only 1 communicates regularly with us and one other is pretty good.  One doesn't communicate at all.

Grades, when properly administered, are a very good way of keeping track of a students progress.  Of course this needs to be followed up with a parent teacher interview to get the details but a report card without grades?  Kids need to know where they stand.  If they are not doing well they need to know it so they can correct the behaviour.