Most coins were still fresh and spouting off about their potential in 2017. There'll no doubt be some bonkers pumps but I'd love to know how buyers and hypers justify it to themselves.
Most likely there will be a bunch of new coins for this exact reason. This has already happened in the past. Look at Dan Larimer for example. Launched BitShares, made some profit, abandoned the project, and now it is bleeding out. Launched Steem, made some profit, abandoned the project, and now it is bleeding out. Then he launched EOS, and for reasons unknown, a bunch of idiots poured money in to it and made it the most successful ICO ever. Now, the value of EOS against BTC is constantly falling. No doubt Larimer will take his profit and leave before long. But when he launches his next project, I have no doubt a bunch of idiots will jump on that one too.
Having said that, coins don't need to evolve, develop, have a working product, or be in any way actually useful, and people will still throw their money at them. Look at TRON, EOS, BCH, BSV, and so on.
This space is far from rational. A few empty promises and a shiny website is all you need.