Probably because its off-topic? I mean technically it is, and if anyone thinks an ICO is a scam, it should be in scam accusations only perhaps?
Is it really off-topic? Even I didn't know that

Talking about an ICO being a scam in a bounty thread makes it off-topic, doesn't it? It would make more sense for such warning to stick to the ANN thread and its scam accusation topic. Right?