You're missing the point. The problem here is the non-Canadian spouse who cannot work in Canada (no work permit). Hence the need for an outland application. Plus not all Canadians can just go and get a job (to cover a whole family on their own). The Canadian job market is not the best. Let's say a Canadian living abroad got disabled and the couple decided to move to Canada say for better accommodation of disabled people. Here the newly-disabled spouse can't work so the income is from the non-Canadian.
The Canadian would be responsible for signing up for disability payments and finding other sources of income through spouse or family. Many countries require a decent salary to sponsor your spouse. In Canada you have to prove that you can support your family without welfare. In most places you can get a minimum wage job if you are Canadian and most likely speak English or French. It is not too much to ask.