As Li Ling said, he had been curious about it when he first learned about these wars that the demonic sect hosted. It was one thing for Wars of Conquest since they were opening up living space for people and could generally be seen as positive, and it was another for Wars of Contest which was their unspoken agreement to train each other's forces and flex their best disciples coming up.
But Wars of Annihilation were definitely against the general moral code of righteous path sects, but nothing that Li Ling had seen in his brief research on the Six Paths 'forums' had stated that they should be wary of righteous sect enemies.
Likewise, when he came over, even Pang Wen did not mention anything of the sort, and no matter how you shook it, Pang Wen had some vested interest in Li Ling surviving and returning because that had to do with Pang Wen's benefits.