I think you are being misled by the labels here. Nobody here has been claiming that cultivated observations cannot have scientific value.
“Research grade” has a specific, somewhat non-intuitive meaning on iNat. There has been a lot of debate about the labels, and whether “research grade” vs. “casual” reflect the intended meaning. You will find countless forum debates about this. If you have new ideas about for clearer labels, I’m sure they would be welcome. But first you have to understand what the underlying categories mean.
“Research grade” is not a judgement about the scientific value of an observation. It merely indicates that it meets certain pre-defined criteria and will be shared with other databases like GBIF: 1) the data is complete and accurate (i.e., date, location, recent evidence of organism, etc.), 2) it has a community ID at species level or below (or below family level, if users have clicked the box “ID cannot be improved”) and 3) it is wild. The last criterion is connected with the preferences of GBIF.
Thus, by definition, “research grade” excludes non-wild observations. There is no “bar to clear”. It is not about “merit”.
Scientists using “research grade” observations still need to check their data set for wrong IDs, anomalies, etc. – the label does not guarantee quality. It is meant as a way to select those observations which fulfill the minimum criteria needed for usable data.
There is nothing that prevents non-wild observations from being used by scientists. It is a bit more work to select the correct parameters to access them, but the data is there and available. Casual observations are not “excluded from the historical record”. Users are not forbidden from uploading non-wild observations.
The fact iNat lumps non-wild observations under “casual” together with observations that are missing data (date/location) or have other issues is a problem. There have been many calls to change this. There have also been requests to allow users to set defaults that include both wild and non-wild organisms rather than just the default “wild only” as is the case at present.
The reason you are not getting resonance for your suggestion is not because users think that cultivated observations are meaningless. E.g., see this feature request full of posts by users asking for specific changes in the way that non-wild observations are handled. Perhaps some of these proposals would satisfy your desire to see non-wild observations made more visible on iNat.
The discussion is going in circles because your arguments seem to be based on an incorrect understanding of what the “non-wild” label on iNat does and what it means and because you seem to think we are all discriminating against non-wild plants when we are not.