Both Golem and Dash are really successful projects - at least when we are talking about their marketcap and Gnosis is not so far behind these two.
You have to realise what you are saying is based on what you can see only. Of course if a few people have a huge share then they can make it appear to have high volume and rising prices. So your statement regarding their apparent success just proves that people are easy to foil and suck into their schemes. MC is another tool they use to endorse their insider success. You can never know what success they are having because you do not know how much they own and how much they are just trading up between themselves.
Dash has actually created some things that are useful so this can explain some people over looking their instamine in some way.
Golem was perhaps not a full scam since ICN bought most of it in one hit and maybe that was not golems fault.
However ico's can not be closed ended because it leaves it open for super manipulation by a few whales.
TBH icos on here are totally open to manipulation anyway. Just wide advertising and open endedness makes it a little harder for them to make their own markets and manipulate everything you see.