Thanks for this pointer. We looked at your feedback and decided not to accept it for the following reasons.
GODI only evaluates the most representative dataset that would allow the data to score highest. We do not consider data for assessment that is not available for free, for the reason that we would need to pay our reviewers to do so and we would need to apply this approach to all submissions.
Therefore if machine-readable data needs to be paid for, we won't consider this data for assessment, but will take a note in the comments.
As our reviewer @codrina notes in her review diary, the use of WMS (and I assume WMTS is conceptually similar in that it displays maps online) conflicts with bulk downloadability. Codrina also elaborates why WMS does not allow for a meaningful download.
I'm not sure whether Codrina would consider WMTS an open, machine-readable format (I assume embedding PNG in the WMTS service does not fall under this category, but I leave it up to Codrina to give a better answer).
So there are some trade-offs we need to take into account when picking the most representative dataset. I would refer the assessment to the WMTS service (available for free and hence accessible to the public).