The lack of value for funny internet coins doesn't come from it being digital, it comes from being absolutely worthless because noone wants to take it. When a government, a physical entity is formed and says "the US Dollar is the currency we'll use to exchange goods", you have value in the USD because you know you're going to be able to use it. You'll be able to buy your lunch with it, because the state you live in says that you have to take it.
Your bitcoin only has value because it can be used to... have more value. It's worthless, and should speculation be gone, you'll go back to it being an unused toy.
Dollars have value because they force you to pay taxes with them. They used to be valuable to foreign nations, because the oil cartel OPEC used to force them to use U.S. Dollars to buy oil. Nowadays nations can use Dollars, Rubels, and Yuan.
