I wouldn't want to comment on whether or not Ontario's provincial nominee program is effective or ineffective, although when the basic data comes forward it will suggest an extremely high retention rate. The Ontario provincial nominee program has historically been very small, so data on economic outcomes and so forth would be very preliminary at this time. You always need a number of years of data to see how people are doing. The Ontario provincial nominee program is very new and very small, so we probably wouldn't have meaningful statistical data.
Why Ontario chose not to begin a provincial nominee program in earlier years when other provinces did is best asked of the Province of Ontario. We have to remember that at that time Ontario was far and away the largest destination for immigrants under federal programs. Ontario still receives a far higher percentage of immigrants than their percentage of Canada's population. That has been changing a little as migratory patterns have shifted in the country, primarily toward western Canada, as has the Canadian economy, investment, and other things. Immigrants tend to follow jobs, as we want them to.