The teachers aren't deliberately trying to give children dyslexia. But neither did Blumenfeld say that they, the teachers, were trying to do that.
Go back and read his sentence again. He said teaching methods are doing this. The teacher is simply the carrier wave -- the user of the methods. They know not what they do.
The question you might want to ask is who develops these teaching methods? Where are they developed? Who finances it? Who controls the "research" that supports it?
I still don't believe that there is a conspiracy among the educational establishment to deliberately give kids reading disorders.
In my opinion, the harm is caused by incompetence and disinterest, not active malace. But, as I said, that's just my opinion.