I was thinking of these too. Despite the engineering achievements their environmental impact has been often regarded as disastrous. From town planning point of view, there are also multiple points of criticism (lack of public spaces, uninspiring architecture, lack of transport concepts etc.). I wonder how this should affect our judgements of what otherwise would be comparable with historical megalomanic projects. Just for comparison, the building of the Moai on Easter Island largely destroyed the island's ecology, rendering it barren and largely infertile. I don't think anyone would come up with this argument against inscribing the Moais though.
For understandable reasons most of us forum members, who were raised and still live in functioning democracies, have a strong (justifiable!) bias against authoritarian regimes. The UAE, with its justice system partially based on Sharia law, exploitation of foreign workers, wealth based on the export of polluting petroleum etc., raises a high degree of antagonism, which might lead us to judge its monuments negatively. However, would we apply similar standards to Western sites which evolved in similarly repressive environments (or worse)? Should the political/social system of a culture reflect on the OUV of its monuments?