Potentially it's up to 85%, but let's put that into real dollars.
As an individual creator, the average amount a writer got from Access Copyright this year was $350. That may not sound like a lot of money, but it's a lot of money for me. If you take away 85% of that, you're left with, what, $60? It's a big cut into my income.
Aside from that, over the past decade or so I've been invited by educators and by schools to come in and do workshops and to do reading. Obviously they think my work is good; I've probably taught 25,000 students. And I have arrived in classrooms where, in advance of going into the classroom, my book has been photocopied for every child in the room.
So with all due respect, it does happen.