People in power and those who are rich (even if they are "fiscally liberal") will not want to let go of that, and people who are poor will have no way of becoming equal to those who have more now if we just got rid of money immediately. Getting rid of currency would make it so less people will have to/want to work, and our world would not properly work anymore or be able to move forward. Innovation would no longer exist and companies would not be able to give products we need to keep moving on further in the progressive world we live in today. If you want to take a step backwards, then just gather a group of people and do what Pol Pot tried to do in Cambodia (and see how that all works out for you).
So far, I have found a grand total of one argument on the 'no' side, which states that we should use barter instead. Well, there is a reason that barter is no longer used, and it is this: money acts as a helpful medium between selling things and buying things; so that instead of, for instance, trying to find someone buying apples AND selling shoes, you can find two different people: one who wants to buy apples and one who wants to buy shoes. This is substantially easier, and is the reason that money exists.
A debate on communism, however, would be much more interesting, and I'll put out my first argument in favor of capitalism: Innovation. In communism, there is no incentive to innovate -- you don't get anything more for creating a genius new invention, while in capitalism you clearly do.
We need money to pay for shelter, we need money to pay for our food, we need money to pay off our bill s, we need money to pay for medical aid.
I could go on and on. Basically, money is one of the most important things in our life.
We can trade like the olden days! They got along just fine! Did they use money? No! So why should we use money? Money ruins us. It makes us greedy people. We should not have money. We are better of without money. What do you prefer: Greedy humans or Happy humans?