Pronunciation is everything, it's all important. A grease-monkey mechanic with good pronunciation would be worth ten degree teachers with bad pronunciation. That said we don't know that Turnoi has bad pronunciation do we? I imagine by looking at his writing and knowing something of his credentials he's word-perfect.

Yes, pronunciation is everything, it's all-important in the classroom.

I did say Turnoi's pronunciation was PROBABLY not up to scratch as he's a non-native English speaker. Re his writing, I can't agree with you - he makes the kind of mistakes that are typically made by speakers of English from non-English speaking countries. Re his credentials, I'm not sure if they're above board as I haven't personally checked them out.