Points based systems lend themselves to abuse anyway-not hard to get into Aus or NZ if you have an HND in Joinery or Hairdressing as they have been classed 'in need' but if you get offered another job there's no real way of forcing you to do them once you have your visa and get offered another job.
When I used to work for NZ immigration there was a points system. People had to prove they had worked (iirc for two years) in their respective field to get a permanent or indefinite visa.
Not sure how it works in oz or how the UK will operate.
Points based systems lend themselves to abuse anyway-not hard to get into Aus or NZ if you have an HND in Joinery or Hairdressing as they have been classed 'in need' but if you get offered another job there's no real way of forcing you to do them once you have your visa and get offered another job.