it doesent have to be inviting. if someones gonna join they should join, if they are offended about it sarcasticlly saying they are a FAILURE they can cry about it. every jam is the same which is not good.
Typically you want game jams to be inviting because you want people to join them and submit to them. When you open with calling people you don't even know a failure, it's kind of hard to think "oh yes, this is worth my time, and the people running it are definitely not unhinged."
It sounds like you're projecting some kind of inferiority complex onto a game jam, which is a very odd place to do it.