. And the courts continue to interpret intellectual property law (in my opinion and in the opinion of some commentators) largely based upon a general feel for whether someone is "cheating" within the norms of business and their industry.
For this reason it would be inadvisable to create something like OSRIC without use of the OGL. With the OGL, a defendant can point to the SRD and the OGL's license to make use of its contents.
I'm not saying that some Seattle judge might not say, in regards to something like OSRIC - "Hmm, looks fishy to me - must be infringing!" - far stranger things have happened. Judges make all sorts of rulings. But in this case the legal basis for such a finding within existing law would be extremely weak.
Note BTW that you can write software to have the same mechanical effect as existing software, and not infringe copyright. Copyright subsists in the code, as a literary work, not in the processes the code effectuates.