Coinbase charge 2% for this service. There is absolutely nothing to stop you just buying and holding the same coins in the same proportion, and therefore achieve the exact same returns, without having to pay the fees. This will appeal only to the most newbie of investors.
It's justifiable for coinbase to favor ETC, which is a better coin than new tokens like Stellar, Cardano or IOTA.
The reason they chose ETC is because it was trivial for them to implement it since it is so closely related to ETH. The same was true of Bitcoin Trash. I wouldn't be surprised if Bitcoin Gold is next for them.
I wonder if there will be an insider trading scandal like last time?