Today everyone can and usually does criticize "cause vs effect" whenever a study doesn't fit into his world view.
The discussion usually is omitted in journalistic articles anyway, so it's easy to say for readers that the scientists just "have no clue".
For me it looks like this research is looking for interventions. They are not just trying to understand intellectual development, but what can be done to improve early education. They succeeded at that. They didn't succeed at satisfying romantic and simplistic understandings about a genetic basis for intelligence.
The discussion usually is omitted in journalistic articles anyway, so it's easy to say for readers that the scientists just "have no clue".
For me it looks like this research is looking for interventions. They are not just trying to understand intellectual development, but what can be done to improve early education. They succeeded at that. They didn't succeed at satisfying romantic and simplistic understandings about a genetic basis for intelligence.