I agree with you. It's okay to base characters off of people, as a way of inspiration for a character. For instance, the main character's father in my comic is based off of my father. A lot of the story is based off of my childhood, too. I've just turned it to extremes, where the design of the character looks very similar to my father, but not quite, and his desire for his son to do sports is a little over the top instead of reasonable. You could also take Gravity Falls for instance. The whole story for Gravity Falls is based off of Alex Hirsch's summers with his twin sister in the woods, but for the show he turned it to extremes with the paranormal stuff. I think he also said Grunkle Stan was based off of one of his actual uncles? I can't remember, but yeah. So it's totally doable! I think where it can become a problem is where you base a character off of yourself, especially the main character, and just make them super awesome and flawless. That's what you want to stay away from.