What about social services? We have public health care in Canada and seniors are the most expensive. Plus, with no industry where are they going to get medication and food? And it's not all seniors, the person in the article isn't leaving because he scared he won't be able to find work elsewhere.
So they also have a bunch of non-seniors they have to support as well. And no industry for them to participate in, whereas elsewhere in the province they could contribute to the economy and pay taxes. Instead of just being an economic drain on the state.
There is a reason the province decided it would be more economical to offer them money to leave than paying for the services for them to stay.