There are two degrees of forced.
a. can't create the listing
b. continuous dunning to add catalog linkage
Three things that go wrong:
1. The item isn't in the catalog, although it belongs in a category which requires the catalog.
2. The item doesn't meet the catalog description, even though it has the same UPC # and may have met the description at some time in the past.
3. The catalog description is huge, and completely obscures seller's textual description.
For sellers who sell used stuff, the first one is very common. The thing is from the '50s. It ain't in any catalog. Of particular note: collectibles/advertising.
Sellers of used stuff frequently sell something which varies from how it was originally sold. Missing manual, for example. When the description shows the manual, the listing is inherently confusing. When buyer complains that the manual was missing, it is of little help to point out that the manual wasn't shown in the picture.
Even when seller might like to enlighten buyer by providing a more accurate description, anything written by seller is in great danger of being shoved way to the bottom by the volume of catalog description. Potential buyers frequently reach the glaze point well before hacking all the way down to seller's description. They hit "buy it now", and end up disappointed (with seller paying the price).
There needs to be an override, or at least a way to put the discrepancy list ahead of the catalog data.
Observe that "item specifics" works fine in this regard. The dun can be turned off, when it is inappropriate.