Aren't there things other than 'experts' and 'novices'?
It is possible to be an experienced web developer without being an expert at databases, for some reasonable definition of 'expert', sure. I think so anyway. Do you find that aggravating?
Whether it's possible to be an experienced web developer while being a novice at either 'databases' or 'data design' (are those the same thing? you said the second, OP said the first) is open to debate I suppose, but is not implied by the OP.
It is possible to be an experienced web developer without being an expert at databases, for some reasonable definition of 'expert', sure. I think so anyway. Do you find that aggravating?
Whether it's possible to be an experienced web developer while being a novice at either 'databases' or 'data design' (are those the same thing? you said the second, OP said the first) is open to debate I suppose, but is not implied by the OP.