I've not made my mind up about this, and I've had the privilege of teaching little, and teaching students with elite educations who did not have these problems.
From my own recollection, being drilled in arithmetic made me bored and rebellious in class. Polynomials got my attention, and transformed the way I did mental arithmetic.
The thing about constructivist pedagogy is that I can see how it might be successful, and produce enthusiastic, resourceful students, but it seems to place huge demands on teachers to get that result. We can't fill any country's classrooms with hundreds of thousands of Seymour Papperts. So choice of curriculum has to be pragmatic, fitting the needs of the students you have with the abilities of the teachers you have. And throwing out today's practice because of the dream of a brighter tomorrow sounds unlikely to work out well.
But I don't know enough to feel I can pass judgement. No doubt when my daughters reach school age, I will feel differently.