They make those coins and they the majority of the developers make their own money. Many thinks it is useless that can be prevented. Many argue about the high costs of creating coins and tokens. We need to move forward and make sure cryptocurrency will evolve to something more powerful.
making a separate coin, is an opportunity that the developer has to develop their business. by making coins themselves, the products they have become more valuable. so, some people just need to buy their own coins, before using the products they make. many reasons for making a coin.