One thing I've noticed is that amateurism is distinctly not an American aesthetic. I think this is the flip-side that informs American taste for Formalism (professionalism), and I think it relates to the distinctly American distaste for central planning.
I think the bottom up anti-centralism of the US casts everyone a priori as an entrepreneur, and likewise "skill" and legitimacy is not associated with public institutions per se but rather with the successful entrepreneur. If we were to take art for example, then the MOMA, Guggenheim etc exist as private non-profit organisations with a board of trustees. It is ultimately a creation of successful industry.
On the other hand, this constructs the amateur as a failed entrepreneur, which is to say merely unskilled or inferior. That is, if everyone is constructed as an entrepreneur, the distinction between the amateur and the professional is only quantitative ie in terms of skill and talent and how much money you make, rather than qualitative. Here Mike Smith is probably a good case, representing the entrepreneur as amateur, and especially since his work was neglected for too long and dismissed as amateurish.
In cultural contrast, we might take the English amateur (the hobbyist) who represents the idiosyncratic over the socialised / normalised / public sphere. Here the amateur represents the inner private life of the domestic as against public life (not the market), which is the personal and the biographical ie what is not fit for "public" consumption. Grayson Perry being a good example.
Perhaps this isn't borne out by the facts? - particularly with reference to Institutional Critique and how it regards institutions. But to me the collector, a figure steeped within 19th C naturalism and the European public institution, makes Mark Dion's work seem very British. Perhaps I'm wrong.
The Australian amateur is probably related to the Australian artist which I long argued comes out of the DIY man in the shed. Here the amateur is opposed to the consumer (why buy something when I can make a perfectly good (imprecise and wonky) version myself?!) Perhaps this relates to a historically ingrained respect for labour, and has persisted in an amateurish maker culture. So does this make the Australian amateur primarily opposed to industrial production?
I started thinking of this because of some lukewarm responses by music writers here to BSR releases, particularly those releases with an interesting sociological context. Here, where everyone is expected to have a jazzed up personal narrative (..and from that day on I knew I was born to X) and be an a priori producer of sorts (I'm a singer/ novelist / artist, yes can I take your order?) any interesting conditions of production are levelled out. The idiosyncrasies in the music don't come across as formalising and illuminating a particular context in which it was produced, rather, it just comes across as another amateur who can't make to spec. Here spec not being mass expectations, but niche, being an equally formalised domain.