The great Australian cafe war: he thought he was the best customer ever
theguardian.com
theguardian.com
I'm not fussy about my coffee, I go to the same place because I like the staff there.
In addition Australian's are known to be coffee snobs, anecdotally I've found even those that are not big coffee drinkers tend to be quite particular about the taste of their coffee.
If coffee roasting and preparation is held in high value and seen as somewhat of a craft it makes sense for Australian's to hold loyalty to particular roasters/baristas/cafe's. To draw a parallel, when getting a haircut many people will return to the same person if they are happy with the experience/result.