Why do some people feel that Ebonics is never appropriate?

seriously ebonics has a structure? i have never noticed that and most people who speak it probably don't structure it either if you ask me it shouldn't be called ebonics it should be called wish i was a gangster talk ebonics is never appropriate people feel it isnt appropriate because it isnt proper english since there maybe different dialects but there is only one proper type of english can you name another dialect that isnt criticized?