Teach to test + inflated grades - If that turns out to be true, then I suppose that is what parents want. Who else should be the one deciding how/what students are taught?

Weaker students - Maybe. But if weaker students are being overlooked then that could also create a market opportunity for other teachers to focus on those weaker students. Again, I would be hesitant to predict any specific outcome, only that teachers would be more responsive to what parents wanted.