Maybe the gap you are seeing is a regional thing?
In central Europe, I see plenty of users who know the more common species across many different taxonomic groups in their region (often through their own observing activity) and whose IDs cover a rather eclectic set of organisms.
I don’t think it is accurate to divide IDers into generalists who never provide IDs more specific than order and specialists who don’t recognize anything outside their particular family of interest. I see lots of people who both have special interests – groups they are especially good at – and also do more general IDing outside these areas.