The obvious reason is profit, crypto market is at initial stage and can give multiple return in short period of time. Second its blockchain technology can reduce cost of many project and enhance efficiency. So it's better to become part of it at early stage
Yes, bottom line here is all because of profit. If you will just think, what type of investment that allows you to earn huge profit in a short period of time? You can't earn huge profit in a stock market, real state or even investing in gold for a short period of time. However, investing in cryptos doesn't guarantee you that you'll really earn huge profit in a short period of time once you've invested in it. It only depends on your strategy if how much you'll going to earn. And because of that, people were so crazy in cryptos because they wanted to earn huge profit.