I hate Ripple tbh, it's a centralized coin that works against what crypto has the potential to be in my mind. I think Neo, UBIQ, DRGN and ETH are all pretty good and safe investments for 2018. I would put 50% in BTC and maybe spread the other 50 between the four coins I mentioned... But that's just me. BTC should have a really good 2018!
Question is not weather the coin is centralized or decentralized or what principles it has and what are particular goals of one coin. Question is can you make money? Are people going to buy and invest into ripple and the answer is yes, from my perspective there is money to be made. As I said let the man think for himself as who knows if trusting random people over the internet is healthy for his investment.