Avoid at all costs and, more importantly, learn to spot the signs of these scams, they aren't exactly subtle but newbie FOMO and inexperience means that these scumbags are often able to fool many into parting with their bitcoin to buy or mine-and-hold these useless coins.
I invested so much into SIGT, Look how low it is still, 900 Satoshi? Why didn't you tell me it was a SCAM sooner cryptodevil? The only ones that got richer is the DEV's.
I responded to a DM somebody sent me alerting to the fact that this clonecoin had been fleecing ill-informed newbies, by investigating and posting my findings immediately in order to warn them. There are so many scam operations running in this industry that it is nigh-on impossible to know of them all and, as you can see in the Signatum thread, and most other scams I have posted warnings in, the response from the fanboi and scammer shill accounts is usually an aggressive attempt to keep burying these warnings as quickly as possible, requiring even more of my time and attention maintaining a persistent presence for these advisory posts in order to ensure the majority of victims are alerted to the facts.
Scammers are highly motivated to discredit and demean any threat to their ability to continue defrauding their victims. Add to that the mix of newbie fanbois who convince themselves it cannot be a scam because they've invested so much money into it already, and the chorus of 'shoot the messenger' is supported even further, adding to the difficulty in promoting the truth within such threads.
This is why there is little point in trying to tag all scams, because there would only be time to post the occasional warning in each, which would be swiftly buried.
Everybody wants to believe they can get in on the ground floor of a coin which will 'moon' to stratospheric values so they can get rich without having to do anything more than click on a few exchange trades. If the coin has no unique and innovative tech which serves to provide a new way to solve an existing problem, or doesn't have a viable commercial platform and economic model, it has no value whatsoever and is being traded solely on speculative hype and lies, constantly looking for 'greater fools' to sell on to.
As i said, learn to spot the signs, they aren't difficult to see. You just have to take off your FOMO-tinted spectacles.