none of these countries would recognise foreign ratings without jumping through hoops
I cannot speak for South Africa, but I believe you are wrong about Australia, which issues a
lifetime "special pilot license" on the basis of other ICAO countries' licenses and medicals. I got mine in 2002, on the back of my Canadian PPL. It is a
paperwork validation, which can be done without making prior arrangements. The SPL doesn't allow flight training for extra ratings , but would be fine for those interested in time-building. Anyone wanting to earn a multi-rating or whatever can convert their foreign ICAO license to an Australian one without too much difficulty; see further
Flight Crew Licensing Procedures Manual.
Apparently there is a minor hassle
unique to UK pilots, but that is the fault of the CAA, not the CASA.
For obvious reasons, I am not personally familiar with the Canadian process of recognizing foreign qualifications (I think Gertrude the Wombat is), but to the best of my knowledge it is neither time-consuming nor arduous to obtain a "Foreign licence Validation Certificate" or a "Limited Term Private Pilot Licence"; see further
here. While those documents have the disadvantage of being time-limited (unlike the FAA and CASA equivalents), that is of little or no consequence to someone who just wants to come here to build time or earn ratings on a one-off basis. And anyone who needs or wants a permanent Canadian license can obtain one quite easily: see
CARs section 421.26(9).
The FAR §61.75 pilot certificate is a fine thing, and I am glad to possess one. But it is certainly not unique, and no reason for choosing to fly in the USA despite all of the restrictions.
MLS
P.S. to our American friends: my distaste for all of the restrictions imposed by the TSA et al. is not intended as a denigration of the friendly nature of most Americans or the quality of instruction available in the USA. I think that it is a shame that your flight schools are 'taking it in the neck' as a result of political expediency.