If people stops buying bitcoin there will be a possibility that bitcoin will die, the value of bitcoin may decrease and all of a sudden it may lose its popularity and die. Other cryptocurrency can replace bitcoin, it will be a big impact if a large percentage of people starts to hate or not to buy bitcoin because it will lead to the negative image of bitcoin and the lack of support to bitcoin.
But I think that if people stop buying Bitcoin, other altcoin will no longer exist in the market Cryptocurrency. At this point, the Cryptocurrency market will be shattered. Bitcoin is the leading digital currency today, although there are many other altcoins out there with more useful features than Bitcoin, but the Bitcoin brand has deepened the hearts of many investors. And they will never stop buying Bitcoin as you think.