>>40035675GT was considered a flop because it wasn't moving merchandise.
When Dragonball Kai started, it was getting ratings mostly equivalent to One Piece, which it shared an hour block with. It got way higher ratings than Pokemon DP did at the time. Yet it got canceled after the Cell arc because it was "a flop".
NOT because of its ratings, but because Dragonball merch sales actually just kept dropping at the time, making it very clear to them having this show on the air wasn't making them any money.