That's somewhere around my cut off date too, but not in terms of gains. I don't believe 2020 is enough time for the gains some people are dreaming of. I do think we'll have a much clearer idea of what Bitcoin's fate will be by then.
If there isn't any scaling and even more centralisation then I'll be walking away. If it can't evolve then something else will.
We are not going to live forever. If in 2020 bitcoin is not making a lot of people rich, then who fucking cares? Might as well jump in front of a train to be honest. How else im going to keep dealing with the rat race? I don't want to spend the rest of my life working only to find out im not even a millionaire yet with 21 BTC in 2030, and for that to happen, 2020 means at least 5 figures.
Otherwise, if that doesnt happen, OP is right. We are going to need an altcoin that makes us rich by taking an huge risk.