How can you argue that globalization is bad for developing countries?
You can argue this in at least two ways.
First, you can say that globalization exposes businesses in developing countries to competition from rich countries. This competition can overwhelm the firms in the developing countries because they do not yet have the experience and the efficiency needed to compete with the "big boys."
Second, you can say that globalization lets rich countries simply use poor countries as colonies. The rich countries do things like using people in the poor countries as low paid, unskilled labor. They do not do anything that will help the poor countries develop. Instead, they simply use them however they can and then move on to some other country if that seems more profitable to them.