Because if the Chinese were treated as badly in Australia as you claim, the amount of Chinese students in Australia would not be at unprecedented numbers. The number of Chinese students enrolled to study in Australia this year is higher than from any other country and is up 12% from last year.
1. australia does not host higher numbered students than *any* other nations, in 2017/2018, australia hosts ~200,000 chinese students, the US hosts ~350,000 chinese students.
2. considering chinese students spies is the work of some australia/US politicians, not the educators.
3. the politics effect already shows up in educations, many chinese students cannot get visa or any response from the embassy when they had received the invitation letter.