Ah true, maybe they have higher operating costs on pantograph and/or the power lines maintenance?
(I don't fully believe GP's comment of "The engineer that can solve this problem will allow top speeds in the range of 400/500 kph on /existing/ TGV tracks.", as narrow turns is probably a bigger contraint than the pantograph problem. Maybe a few of the more straight lines can benefit, but there's more constraints to solve before taking turns at 400/500 kph!)
(I don't fully believe GP's comment of "The engineer that can solve this problem will allow top speeds in the range of 400/500 kph on /existing/ TGV tracks.", as narrow turns is probably a bigger contraint than the pantograph problem. Maybe a few of the more straight lines can benefit, but there's more constraints to solve before taking turns at 400/500 kph!)