You are presuming a fact that does not exist.

If no one wants to invest into bitcoin or inject capital into bitcoin, then the presumption is that bitcoin goes to zero, and I would be stuck with whatever amount of value that I had invested.

I will agree with you Snowshow, that anything is possible, including the scenario that you present.

However, I will also state the case that any kind of investment that we make into anything, whether bitcoin or any other asset/currency, we should try our best to invest based on the various probabilities that we assign to various scenarios, and so maybe the scenario that you outline has about a .001% chance of happening at best, so my investment should account for that.

Now if you are making the mistake of assigning 1% to 10% probabilities to the scenario that you outline, then I would suggest that you are way overassigning such a probability to such an event that is way less probable than you are making it out to be. 

If we take you at your word Snowshow, and you are actually genuinely worried about the non-existence of bitcoin (and therefore its non-value) then you seem to be engaging in even a worse fallacy than the one that I have outlined above because you seem to be placing some higher level of likelihood that bitcoin is either non-existent or worth zero. 

You are really going to get fucked if you are really investing in that kind  of a way because bitcoin continues to be one of the best upside asymmetrical bets that have ever been available to normies (presuming that you may well be a normie).  In other words, you do not even need to invest much in bitcoin in order to have the potential to financially profit stupendously and yeah, we can poo-poo profits all that we like, but the essence of the matter is that if you have profits, then you have options and you can choose however you like to use those profits or not to use them.  If you do not have profits then you presumptively have fewer options.

I can even provide a brief overview of my own investment into bitcoin that started in late 2013.  Initially, I did not really know what bitcoin was and I thought that it might be a good hedge against the dollar, so my initial allocation into bitcoin was intended to be invested over the next 6 months while I looked into the matter.  After my first 6 months investing into bitcoin, I pretty much decided to provide myself with another 6 months that had a similar allocation as the first 6 months, and so by the time I got to the end of my first year investing into bitcoin, I had been studying and considering the matter and towards the end of the second 6 months, I decided that I would aim for an allocation that would be about 10% of what I considered to be the value of the quasi-liquid portions of my total investment portfolio.   

Towards the end of 2014, I had pretty much reached my 10% allocation, so at that point, I had considered myself to have had been sufficiently allocated into bitcoin and there was really no need to allocate more than that... however, many of us realize that the end of 2014 and the whole of 2015 saw BTC prices that had bottomed out and had stayed pretty much in the mid-$200s for most of that time.

The punchline is largely that I had decided to largely just continue dollar cost average investing into bitcoin through 2014 and 2015 and by the time the end of 2015 came, I had ended up overallocating into bitcoin because my amount had reached about 13.5%... so in that sense, it seemed to me that overallocated had given me options to be able to have flexibility with that extra 3.5% that I had into bitcoin... - nonetheless, BTC's price performance between late 2015 and 2017 had largely been UP, so in that sense I had reconsidered the way that I would manage my BTC holdings in such a way to just allow my winners (meaning BTC) to ride rather than reallocating.. and so largely that has meant for me that my BTC holdings had gone up to nearly 90% of my overall holdings and then corrected back down to 45% and then returned back to somewhere in the 80% and 90% arena..

Sure, I engaged in some other portfolio managing practices along the way, but in the end, the BTC holdings end up giving more options because it's no real skin off of my back because all along I pretty much already authorized myself to allocate up to 10% and then I just allowed my extra 3.5% allocation just to continue to ride.. and sure it seems that I have had various times of shaving off various profits at various places along the way.. and it seems to me that any of the profits that i had been shaving off had mostly been in connection with the 3.5% extra allocation. and not even really meaningfully depleting that amount because it is already allocated and it is drawn from from time to time when needed.. or just when wanted or just  giving more options.

Another thing would be for me to consider if there might be some need to reallocate some of the BTC.. and to maybe give greater weight to the various going to zero scenarios, and sure some of the shavings off of profits might end up  going into various other kinds of investments like property and some other quality of life matters (that might end up falling into the category of consumption rather than investment), so yeah, maybe perspectives evolve with time and how many additional options might have come from the degree to which profits are present and how those profits have been managed including accounting for various other aspects of life that include making sure that cashflow, expenses and even emergency funds are available too.  .. even during periods in which BTC's price performance (and direction) seems to be going down rather than up.