Perhaps in 2017, most people who are interested in new Internet technologies have already entered into crypto. Now the influx of new people has decreased. In addition, the market does not show growth for six months. Crypto needs a new hype 
I think this is the best answer. To grow much bigger crypto needs mass adoption and only way to do that is if people start to use it in everyday life. As it is now most people don't use or even own any crypto currency.