Who got scammed when doing part-time rental work while studying in Australia?

The reason is that I am studying abroad in Australia, and my family's financial situation is average. Recently, I took on some physically demanding part-time jobs, which paid well, but it became overwhelming. On my days off, I just wanted to relax and either use my phone or sleep. Later, I shared this frustration with my best friend, and she suggested that since I am local, I could help by posting rental listings for international students. It would be a way to assist my friends and also help other students who haven't come to Australia yet, so they don't have to go through unnecessary trouble. The result was that when I mentioned this in our class group chat, I was criticized for making money from them. I really don't understand it. I'm just trying to do something within my capacity and make things easier for students. However, I will continue doing it. If any of my friends who are planning to study abroad in Australia want to look for accommodation online in advance, they are welcome to do so.