As long as Bitcoin can be shown to be a hedge against gold, there will always be people who buy it.
People buy gold to hedge against equities and bonds. Gold owners have obviously started buying Bitcoin too to hedge against gold, for what it's worth. Just have a look at the graphs showing the outflow from gold into bitcoin during the media frenzy in December.
The sort of people who buy gold for investment purposes are the ones who will also buy bitcoin simply to balance their portfolio just a little bit more. They don't get emotional about it and will simply split their portfolio like this, for example:
60% equities
30% bonds
6% gold
3% cryptocurrency
The correct statement should be "As long as there are people who use/buy bitcoin, it will continue to exist". Regardless of using bitcoin as a hedge to other forms of investments, ultimately, the users themselves determine it's continued existence.