At the same time, I believe that the artists had to know that, working on a book for mainstream DC Comics, there would be certain parameters they'd have to follow.
If they were genuinely interested in not doing something involving DC characters and in a different format - Then they'd go to IDW or somewhere similar, who have a great history of giving artists fantastic books to display their work in, especially with Ashley Wood spearheading Sparrow and Swallow.
So I don't think creators going to investigate Solo were as oblivious as you suggest. You don't go to DC Comics to check out the idea of working on a prestige-style book and think you'd be doing entirely your own thing.
As it is, this just seems like another case of tarring Didio with the 'STUPID and RUBBISH' brush, whereas I guarantee if anyone else were in his place, people would revile them, too.