I use Flash for one thing only: creating graphic assets in the Library which are assigned class names and exported to SWCs. I do all my development in an IDE (PowerFlasher). A big part of this process is converting Illustrator and Photoshop assets into Flash libraries.
I need to make decisions on a layer by layer basis as to how each layer is imported (bitmap, vector etc), registration points, instance names etc.
And frequently the source files are modified in which case I would only want to select the modified layers for import.
Removing the import dialogs for Illustrator and Photoshop makes Flash CC practically useless for me. A clearer case of "reverse upgrade" have I never encountered previously.