When it chips or gets pitted it rusts. If you bend for flex it will crack the chrome and it will rust. Chrome looks good while it is in good shape but once it pits or cracks it looks worse. Look at all the aftermarket chrome wheels around you. When you see chrome plated steel are they in good shape or do they look like a rusted chrome wheel.
The other down side is cost. That frame will have to be totally striped down, sanded and pollished smooth. The cost in chrome plateing is the prepwork, and there is going to be alot doing a frame.