You might say your friend(s) is jealous of your business, but how about it is something else that they don't know how to engage with it. (Ever thought about that?)

They might not be your ideal customer, or they have no idea how to support you. 

You will agree with me that you also have friends who you don't get to support their business, not because you don't like them but because it's not just your cup of tea. 

Side note: I urge you to show interest and ask them questions. You don't want to be like Susan.