This observation has not aged well, I think. In fact, I think it is fair to say that iNat’s reach in this regard is far beyond anything published by academics in Biology Letters could ever aspire to. Enshrining a default common name on iNat makes it real for a very large community, instantly.
The questions I asked as the OP were rhetorical. I think that the iNat rules around making up common names are logically flawed and out of step with how things work and the conversation around them is deeply conflicted.
So here’s a thought. Common/vernacular names are not historically the product of academic writing. They largely arise from the vernacular (i.e. they are social phenomena), with some exceptions such as the obsessive, unending reconstituting and reordering of names by a community of apparently anally-retentive control freaks who run ornithological organizations in the English-speaking world.
Common names reflect history, local knowledge, flights of fancy and outright weirdness that are part of the human condition. We have binomial nomenclature for keeping track of things; hopefully once we get done gene-sequencing everything it will settle down into some new normal that provides some kind of stable view of things. Getting stuffy about common names is not only anti-historical it is pointless.
I don’t have a beef with authors of field guides making up names. I just don’t like that there seems to be a notion in play at iNat that this is consistent in some way with a policy of squashing suggestions from ordinary folks on a social media platform with truly global reach. It is not. To my mind there are two options: officially make it iNat policy that a foolish consistency is the hobgoblin of little minds and carry on or; acknowledge the social nature of vernacular naming and harness the power of a social network to slap some names on things that currently only sport Latinized binomial labels.
It seems to me that iNaturalist is perfectly placed to harness social processes and get some names on things with a higher probability of reflecting existing vernacular usage and perhaps a touch of whimsy than existing processes. I don’t suggest a free-for-all; more something like the existing Feature Request process where folks can propose and argue about it. My first suggestion would be to accept Mardi Gras Sharpshooter as a name, although some ornithologist will probably argue that French words shouldn’t be in English names so it will end up as the Fat Tuesday Sharpshooter but what the heck, that has its own charm.