They don't care about foreign ownership limitations. It didn't stop TPG securing a local investor, flush with their cash, from almost taking QF private.
The limitation is about as effective as the Singaporean one with regards to Newstar's investment in Jetstar Asia, Dennis Choo, 51% and Qantas the other 49% directly. Qantas exercise effective 100% control of Jetstar Asia, there is nothing stopping that sort of arrange with Qantas today.
Read the guts of the QSA and you'll see the parts they don't want to be constrained by. All of that aggregate majority stuff - maintenance, training, stuff like that.
It's not about a foreigner buying Qantas, it's about wanting to offshore the lot whilst maintaining rights from within Australia.
(f) prohibit Qantas from conducting scheduled international air transport passenger services under a name other than:
(i) its company name; or
(ii) a registered business name that includes the expression “Qantas”; and
(g) require that the head office of Qantas always be located in Australia; and
(h) require that of the facilities, taken in aggregate, which are used by Qantas in the provision of scheduled international air transport services (for example, facilities for the maintenance and housing of aircraft, catering, flight operations, training and administration), the facilities located in Australia, when compared with those located in any other country, must represent the principal operational centre for Qantas;