That's not really true. There are quite a few working visa categories for professionals in engineering, medicine, journalism, higher education, etc. in addition

That's not really true. There are quite a few working visa categories for professionals in engineering, medicine, journalism, higher education, etc. in addition to the lower-skill categories for basic English teaching and "entertainment." The government has also introduced a points-based system that prioritizes visas for people with more skills/experience/income, and has been making it a lot easier to get longer-term visas and permanent residency.