I'm not going to assume creativity isn't your form of income, but have you heard of copyright? Copyright exists for a reason, & copyright is really that serious. I'm not going to stand aside & watch people tie a noose for themselves. I'd prefer to give people a little heads up so they don't end up in much more serious situations in life.
But now for a more selfish explanation... I don't like people getting credited for the time, money & original creativity of my work. Be it in a game or real life where my very source of income depends on this.
So maybe you should take a look at the bigger picture?
This. 100%.As for copying, I think being inspired by others is better than outright copying. Like I did a school design (again, in RS), and credited on my wall the neighbor who had previously done a school design, cause that's where I got the idea, but I didn't do her school design. (Though some elements were necessarily the same, because we both had the same cheerleaders in the gym and bookshelves in the library.)