It seemed clear to me that it needed an Interface Builder equivalent, but Atlas was in perpetual beta and ignored for years, motorola bought them and the 280 north guys went to "hot" startups.
I was really interested in Cappuccino for quite awhile, still would be if it could deliver a working system that was in reasonably good shape. (I'm not saying it can't, but it's apparently being abandoned years ago made me believe I shouldn't invest time into it.)
As you are aware, Atlas is dead and has been for some time. But Cappuccino has always been valuable without it -- virtually everything ever built with Cappuccino was not built with Atlas. Instead, the community poured a lot of resources into improving compatibility with Xcode and Interface Builder, getting many (if not all) of the benefits Atlas would have brought to the table.