It is because these big corporations are visionaries and they see bitcoin as the future of money. The top 1% of the 1% always gaining control and once they see the price of BTC soaring to the moon, they will cash out and take profit. We must know how to ride with the whales.
Do really big corporations, such as those belong to Fortune 500 companies does accepts Bitcoin? From what I know, there is only a small percentage of businesses that are willing to accept Bitcoin in exchange for services or products, payment method likewise. And the majority of this small group compose only of small to medium enterprises. Financial institutions such as banks in general are hesitant to consider Bitcoin as a currency and are now taking actions to make people reconsider investing with Cryptocurrencies. If a normal individual who chooses to stay and be contented with fiat money, I do really doubt that corporations will ever engage with these digital coins or let BTC alone.
Big corporations are still not into bitcoin as far as a know. And those who are into it, are making just a investment and not accepting it as payment or such. We have heard Microsoft lately, stop accepting it, however, they got some kind of payment processor, I assumed Bitpay to handle their bitcoin transactions. I have to agree that bitcoin should be the future, that's why a lot of financial institutions are really interested on it. 2017 show's how bitcoin popularity surges, that's why they can't ignore it and join. However, for the Fortune 500, I haven't heard much noise, and I doubt that they are into bitcoin to exchange to fiat, but just like the rest of us, they see at a investment platform.