Yeah. Same results here. NopCommerce has to do something about this, or at least inform about it. They cannot expect everyone to figure out how to block our search engine crawlers from indexing spec urls. In my case it was legit google crawlers. I seriously doubt the spec urls effects the index rating anyways.
Maybe nopcommerce does require more DB DTU than we want to pay, but it shouldn't be that big of a problem. The category view takes too much power it seems. Another solution, proposed by nopcommerce is caching the categories, but that messed up my ajax filters plugin it seemed. I might be wrong. Will check it on monday.