If the price doesnt rise then the miners stop mining because of lack of profit, Once this happens the network becomes less secure and bitcoin starts dying off. Whats to stop this from happening? Maybe we are getting to prices that cant be maintained with the current user base. I wasnt here at the last halfing and the price will need to be much higher so im not too sure what will happen.
At the start of Bitcoin's life it was worth nothing and was still being mined.
There would still be people such as students in University that would use Bitcoin to get money even small amounts would help them and oter peole own lots of Bitcoin so they would want to keep the blockchain going so there is lots of money for them surely.