The problem is that since the website on which we sit is called iNaturalist, to argue that some are not worthy of that word is a form of gatekeeping. It is by its very nature unkind, exclusionary, when perhaps we ought to be inclusive, especially if we wish to have more users from lesser attended corners of the earth.
I do not call myself a naturalist. For a long time my description read something like just a lady with a little wild space. I am distinctly aware I have no formal education in the sciences so I muddle about dependent on the good graces of others and my own disciplined practices.
But it yields! Five years in, having spent multiple hours a day just sitting and watching, I can tell you in detail about many species. I could do something like this for probably twenty or thirty local species, maybe more.
One could argue that these are not important species, who cares about the Nannotrigona perilampoides, Membracis mexicana, Hamelia patens, Solanum erianthum, Gonolobus barbatus, and the others, that it is more important to have broad knowledge across all taxa rather than deep knowledge of a few less important things (the plants I know are considered weeds), but that is not how my knowledge has been built, and I think maybe there is room for both types, and also room for those who come to just enjoy for a bit.
(Sometimes I like to think maybe we actually need all the types, for balance.)
Tl; dr: Labels are unimportant and fixating on the use of them and deciding if someone else can or cannot use one feels not wholly gracious. But there is confusion, yes, so then I think it is OK to ask, kindly, You say you are a birder, can you tell me more about that?
It is up to each individual to decide whether or not to consider any or none of what I have written.
I am after all just a lady, now with a different garden.