Fair enough, @cthawley. Your points about staffing and curation workloads are well taken. I think my main point is that iNat, for better or worse, by the breadth of its coverage and popularity of its use in many counties, has already positioned itself as a repository of primary information–whether that was the original intent of the creators or not. Passively “allowing people to add existing common names … so that users will be able to find the name of an organism that they already know” might have been an appropriate framework for that new-kid-on-the-block back in 2008-2011. I think the platform has evolved since then.
I continue to support the concept that iNaturalist should not be viewed or held as a taxonomic authority or arbiter. But I believe that iNaturalist has now matured to a point where it can serve as a legitimate entry point for new information such as a common name proposal, within some type of guidelines as I suggest above.