Not recommended by who? Clearly Apple think it's a good idea otherwise whyadd the feature in the first place? And I assume you are speaking for yourself when you say are generally not useful and not needed. Personally, I find them absolutely essential and a vital part of my work and personal photo archive.
I take your point on the dragging images to the icon, but I was moving the concept a bit further by implying an improvement to offer a choice of libraries within the save/import function of Mail. What's frustrating is to have an option, use it regularly each day and then bang, it's gone!
I will follow up on Old Toad's comment.
lasserre