^^ ICO is not a negative so long as they actually engage in business done. Thats pretty much my emphasis overall, excessive speculation sure but too much trade? Not a bad thing
Its very possible for bitcoin to achieve higher values then in 2017, however I would not expect everything to happen all at once. Hurdles must be passed before price can match actual trade done with demand producing possibilities for speculators to become bullish.
The main driver for higher prices is not crypto currency at all, its not clever technology. Its not even the emerging market and addressing those without banking in tradational systems. The main reason Bitcoin is likely to continue past 20,000 'in the years to come' is in relation to dollar and the decline of value occurring from QE fallout.
If you want a solid answer to your question for the long term then look at Dollar reserve, trade balance and QE programs in major economies. If bitcoin can be more stable then the unwinding of QE bond holdings then the price will rise. Think of a set of scales, if dollar is burning value on one side and Bitcoin is merely steady on the other side then value will find favour in a more solid value of Crypto. That does require that Bitcoin maintain steady trade, it does need to lower fees to do that.
mere wishful thinking?
Too much speculation is a negative but over years BTC is capable of rising so long as development continues positively.