Why does everyone say that MDF is not suited for furniture?

I have heard that MDF material is not suited for indoor use such as in furniture. Is it true?

To start with, MDF is cheaper than real wood, but retains most of its texture. It is also water-resistant to a certain extent, and very popular for making cabinet doors. However, it is much heavier, prone to scratches, and does not react well to heat.
Recently, there are growing concerns about MDF’s health risks around the world as well. So, I would suggest you to look for other options for making your furniture.