This is one of the Laws of Consulting, iirc, and it applies to anything, not just design: find something for your counterparts to object to and hand it to them, so that they can feel empowered.

More broadly, it's just political management of assemblies. Most governments do the same with controversial legislation: attach some wildly-outrageous clause to something slightly-less-outrageous, focus opposition on that, then strike it out. You then have the space to pass the bulk of it, which was your real objective all along, while claiming you "listened".