If people starting in the world of web development listing their CSS skills at 90% is hurting you as a UI Designer, it's your job to differentiate yourself from them, not their's to not list their skill at the level they might appreciate.
Starting out is hard, we should help with positive criticism, you are ranting about what they shouldn't do (in your view) but you're not offering advice about what they can do to improve.
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This sounds more like a rant than an advice.
If people starting in the world of web development listing their CSS skills at 90% is hurting you as a UI Designer, it's your job to differentiate yourself from them, not their's to not list their skill at the level they might appreciate.
Starting out is hard, we should help with positive criticism, you are ranting about what they shouldn't do (in your view) but you're not offering advice about what they can do to improve.