There is 6B$ in Bitcoin wealth floating around, surely there are means for funding a few salaries. And that's what is going to happen in the future. Funding will take place through on-blockchain methods, some Cryptocurrency projects do this already. Money and opensource is now tightly connected, but Bitcoiners generally haven't figured this out yet. For more innovative ways checkout Ethereum, Bitshares, Nxt, etc.
But no, I'm afraid you'll have to do a bit more than merely allude to (non-)solutions, or point out how paper gains are enough motivation to keep experts who could otherwise be earning 6 figure incomes, to instead work full time on difficult solutions for free.
That you've taken absolutely no effort to spell out any of this magic success formula and instead chosen to allude to altcoins is sadly typical.
Bottom line: nobody has figured out how to sustainably support open source projects with money, period. In the best case, it's the blind leading the blind. You do what works. And whose to say what works? It's ridiculously subjective.
Said the GP:
> There is 6B$ in Bitcoin wealth floating around, surely there are means for funding a few salaries.
Isn't that exactly what Blockstream is doing?