Thats what I thought, thanks for the advice.The only benefit I found was you could start from seed in a rockwool cube. Or start with clones with small root systems.
As soon as the roots get into the water I go with straight DWC. The pump can get clogged, added heat, and more stuff that the roots love to wrap around (pump, manifold, lines, pump bag if you use one).
Back to back with the same kids I personally saw no advantage for keeping the pump in there. Others may have found otherwise. That was with a stealth bubble system.