Why do I have to go through so much to invite my parents to live with me in Australia?

I migrated to Australia in 2002 and my Parents are close to 70 years of age now, they live in India, my biggest problem right now is I can't call my parents to live with me forever because of Immigration laws and I want to live with them and be their support in this old age. Why can't we have decent laws that supports not only skilled migration but also unique family vaules from overseas. Roughly I spend about $10K PA to support my parents overseas every year, if they were here in Australia, I am sure it would have been well spent whithin Australian economy.
Why do I have to go through so much to invite my parents to live with me in Australia?
Good point. But what about the eldery that immigrate and then suck up healthcare expenses from the system? The problem is the abuse of relationship laws and the fact that there are too many people trying to immigrate into too few decent countries.