I've never worked for a games dev company, but I can imagine the scene where a self-proclaimed 'game designer' walks into the office, with no real development experience. As a grunt, or cog in the machine, I would seriously doubt their ability to turn an idea into a coherent product, unless they had credentials and could 'walk the walk' as well as 'talk the talk'.
My own opinion of a real games designer is someone who has worked on the really nitty gritty stuff, and actually been through the process of games release several times. I'd also expect they haven't become jaded and cynical about the games industry, and can think freely outside the constraints of their knowledge, but without the 'pie in the sky' mentality. I would expect them to be able to guess actual sales figures for different design models (e.g. 2D vs 3D). Most importantly if working with a team, they must have a sound, comprehensible vision that others can really get behind and believe in - whether it's completely original or not doesn't matter.
My own opinion of a real games designer is someone who has worked on the really nitty gritty stuff, and actually been through the process of games release several times. I'd also expect they haven't become jaded and cynical about the games industry, and can think freely outside the constraints of their knowledge, but without the 'pie in the sky' mentality. I would expect them to be able to guess actual sales figures for different design models (e.g. 2D vs 3D). Most importantly if working with a team, they must have a sound, comprehensible vision that others can really get behind and believe in - whether it's completely original or not doesn't matter.