I am not sure the issue is here..
-Grabbing people with good reps is a smart move
It certainly is, but if a scam does happen, then this would do far more damage , as people tend to think, that trusted members would not be advertising a scam.
An example of this is the recent case of dicebitco.in. Just Dice owner dooglus, initially advertised their site in his signature, and the site was able to get 7000 BTC investment, in about 2 months.
That is something, none of the other sites were able to get.
In the end, it was found rolls were rigged and it was scamming the gamblers. Then in also ran away with some investor funds.
Having some reputed members use their signature, makes it look like they are vouching for it(even though they clearly say , they are not, but people still consider it so).