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?
If a DT member is planning on tagging bounty participants because the project is a scam (or suspected scam), I'd say it's not really off-topic. Don't know why something like this would be deleted. Bounty hunters tend to not visit sections other than bounties, so it's not a given that they'd see anything in Scam Accusations.
Edit: On the other hand, bounty hunters probably would still miss a warning like this, even if it's in a bounty thread they're participating in--doesn't matter what size font or color you use. Take a look at how many sig campaign applicants miss "This campaign is now CLOSED" posts. Maybe a standalone thread in Scam Accusations would be better anyway.
I am not against such warnings and it's a good thing that marlboroza left the warning, but when it comes to moderation, mods can't do anything but to follow the forum's policies and hence it was deleted,unless there was a whole another reason for the post to be deleted.
I guess I just disagree. I don't think this is something mods should take action against. The project might be a scam, but by extension the bounty is also scammy and hence a warning isn't strictly off-topic.