Ask HNs: Why do people expect so much from a free apps?

I publish a few popular apps on the play store. They have about ~10k Users. Most people usually say nice things or have legit issues and I try to look at them. However some users will hound me about a feature or a bug. One guy was like I am going to use a different app if you don't fix something by tomorrow. I didn't really reply.

Why do people think they are so entitled especially when it is a free app?