As to the main point of the OP: I agree if we are talking about the TSR/WotC settings. The death of the novels and WotC's refusal to publish something like a new Forgotten Realms campaign setting book really are a weakness of the current edition if you are into lore (or if simply, you have new players you want to introduce to your favourite "adolescence setting").
To be fair: I wouldn't want the flood of setting books from 2e to come back, but certainly I would want more than we currently have.
And, as mentioned above: there are 3rd party publishers that still write solid setting books. So it's really mostly those of us who would like for some comprehensive material about a classic D&D setting who are hit by WotC's shift away from such material.