I think this something that will always result in gray areas, but a line has to be drawn somewhere so that we can all know what captive/cultivated means on iNaturalist, whether or not we all agree on how it should be defined. We might all have a different idea of what the term means to us, but we should share one definition here, and this one is what’s being used so it’s best to stick to that one. Members of the community can discuss individual cases with the observer and vote in the observation’s Data Quality Assessment area.
There have been plenty of discussions on how to deal with verifiable observations of non-wild organisms, and to have a different category for them rather than lumping them in with “casual”. Definitely something we’re still looking into. However, I think that even if a new category that included non-wild organisms was created, it still won’t be turned on by default in Identify and Explore.
The reason that “casual” observations (including ones of non-wild organisms) observations are not shown by default is not to prevent them from being identified, but has to do with iNat’s (and our community’s) focus on observations of wild organisms. I won’t speak for everyone, but I think most users don’t want to see garden plants, pets, or zoo animals when they’re searching through observations. Anyone who wants to see those and ID them can always use filters to surface them.