You can't place document or application icons on the desktop, either, much less drag them to or from the panel, or drag desktop icons from the menu. Never mind that a third — perhaps closer to half — of users probably prefer desktop icons.
However, by far the greatest weakness is GNOME Classic's lack of GNOME 2's pager icon for virtual workspaces. The only way to change workspaces with a mouse is to open the menu and click the link for the activities overview — which otherwise serves no extra purpose. Moreover, while the context menu includes the item "Organize Desktops By Name," GNOME Classic apparently includes no way to edit, let alone create or display virtual desktops' names. The result is that virtual workspaces in GNOME Classic are far less convenient than in either GNOME 2 or 3.
GNOME Classic could still be improved before the general 3.8 release. But its mediocre performance in the beta is unexpected. The decision to drop fallback mode was officially taken because bringing it up to quality and maintaining it as a separate code base was seen as too time consuming by the GNOME release team.
However, at the time, I thought it reasonable to assume that GNOME was also aware of the wide disdain for fallback mode. When Slashdot reported the decision, about the kindest description of fallback mode made by commenters was that it was "non-functional." Many felt that its lack of basic features condemned users who lacked or chose not to use proprietary drivers with 3-D hardware acceleration to a second-class user experience.
Not only that, but Mattias Clasen's comment that "we should not fault people who prefer the old way" seemed the voice of sanity after GNOME's apparent reluctance to accommodate those who preferred GNOME 2.
Yet despite these apparent reasons for optimism, GNOME Classic seems scheduled to deliver its own second-class user experience.
GNOME developers are joking when they describe GNOME Classic as "Flintstones mode," but you don't need to be an English major to hear overtones of disdain for an obsolescent interface in the term, especially when GNOME 3 is being referred to as "Jetsons mode" in contrast.
At the very least, the intent seems confused when one developer warns users that "nobody tried to restore [the] GNOME 2 experience" in one sentence, then in the next says that the intent was "just to bring some 'typical' desktop features in 3." After all, what is GNOME 2, if not a typical desktop, especially in the minds of those who spent the last year looking for a suitable replacement for it? For that matter, why stop at "some" when the results are unlike to please anyone?
What makes GNOME Classic especially disappointing is that doing better would have been relatively easy. For example, if you go to the GNOME extensions site, you can provide the workspace pager by installing the Workspace Grid extension, eliminating any need for the overview mode, unless you prefer a full-screen replacement for the menu. You can also display names for workspaces by adding Workspace Labels, and add a number of applets to the panel, if not quite as conveniently as in GNOME 2. In many cases, you can find several choices for the same functionality.
In addition, there seems no technical reason why GNOME could not borrow from Cinnamon, which is, after all, a series of modifications to GNOME 3. The result would have been a GNOME Classic that honored the GNOME 2 legacy while making it easy to switch to GNOME 3 and back again any time that a user desired. Yet for some reason, GNOME developers seem at pains to distance themselves from Cinnamon, even though borrowing from it would have helped to improve GNOME Classic without adding significantly to the maintenance.
Experienced users, of course, can improve GNOME Classic with an hours' browsing on the extension site. However, the result still falls short of Mate or Cinnamon, and newer users are likely to stick with what GNOME Classic installs — and be discontent.
Unless GNOME Classic improves before the general release, it seems destined to be a disappointment. It easily it could be much more. The half-hearted effort remains a puzzle.