Scam coins:
1) create a coin, the makers then buy it themselves at himself without investment, and as soon as the warrants for the purchase of sell all in one motion. Living example - BCC (bitconnect)
2) create a coin with a huge premine and the creators give all every week for 7% airdrop, and as soon as there is a serious warrant for the purchase of sell a huge balance in one motion. A living example - BTX
BTX and Trashconnect have nothing in common.
As for the premine:
I can say the same thing for the 95% of the coins out there , where the devs have large amout of the coins to fund the dev of the project .
If all those 95% are scams, then BTX is less scam than them , cause at least the devs dont sell them to you in the ICO, but airdrop them to you .So they give you money , instead of taking money from you .