I think the distinction is that sports betting companies are basically casinos, need to guard their edge, and although they will tolerate some moving of lines, they will kick out players who consistently eat their edge, and will rig the lines at a place where they can still profit.

Different from a prediction market like Polymarket or Kalshi whose income probably comes mostly from transaction fees rather than house edge. Otherwise these platforms wouldn't welcome bots so much. Bots => efficient pricing + transaction volume => profit for them