I get the feeling though, that they have forgotten one thing - Bitcoin has a community, and people that will speak out again and again to warn others away from things like this.
There are "traditional" HYIP forums, where people discussed these programs (Bitcoin related or not) - but they are heavily moderated and often supported by ad money from the admins of the HYIP programs. But the people posting there are very aware (usually) that they are taking a massive risk, and it's really just all a gamble - they don't really go out of their way to point out (what should be) the obvious, to the noobs who turn up expressing an interest. In the Bitcoin community, people WILL take the time to do that.
In some ways these new Bitcoin-related HYIPs are more insidious, because they are preying on a new pool of people who most likely haven't been targetted by HYIP admins before. Some of them genuinely think they have found a risk-free way of increasing their Bitcoin wallet values. At least with the traditional HYIPs the admins seem to know that, to some extent, they are really just catering to a hardened bunch of HYIP players who are used to taking the wins with the losses, just like fruit machine or card gamblers.
Well said. This is nothing new or specific to bitcoin, it's just a new arena for the scammers to play in.