I agree - let's see what others think. This same general approach to attachments exists elsewhere in the toolkit. For instance to add an image to a forum post, you must edit your post - and if user's aren't allowed to edit their posts (a bboard parameter) there's no way for them to add an image or non-image attachment. I think that either or both of wimpy-point ("wp-slim") and glossary also rely on the "edit" page for the adding of attachments. But glossary uses GC so I may be confused, it may just be true of comments added to a glossary item ...
So my first suggestion would be that you spend some time investigating other packages for the same UI flaw - *if* you have the time and motivation to do so, of course. It would be nice to simplify the addition of attachments throughout.
The other issue is timing. After my whirlwind tour through the toolkit over the last two weeks, changing about 150 files in order to improve performance and change the tree_sortkey scheme, the code's finally starting to stabilize again. This means it's about time to start getting serious about a beta release.
Changes such as you're discussing probably need to go into our next release cycle rather than delay the current one, which has been delayed more times than I can remember already. We really need to squeeze out a real release.
At least ... that's my opinion. What do you (and others) think? Of course we're going to continue to work on the toolkit continuously, this is just a matter of release timing.