As a person who is not an expert or researcher, I have no personal interest in definitions of captive, cultivated, casual, or research grade. But I would like to be able to go onto the Identify tool to help identify organisms that I can help with, without having to look through so many observations of organisms I'm not at all interested in. To me, the issue is the ability to filter for what one wants to look at, which, in my case, does not include plants in schoolyards, gardens, or universities, zoo animals, human faces, etc. Right now, the only way to exclude those is by relying on people to categorize their observations properly, which many fail to do.
I think the issue of being able to use the filters one wants in the Identify tool is related to, but different from, all the issues about what postings should be allowed on iNat, how to get people to mark their observations properly, and whether people should or should not be frustrated by the way it works now. If it's feasible, just let the individual identifier decide. In addition to the exclusions I requested above, I think being able to filter out observations from people who have just started using iNat would go a long way. Again, others would be free to leave those in.