If we accept that Ford is going to build the subway no matter what, and the province is paying for it, it should have a Lawrence East stop.
Given the development potential at Eglinton & Danforth, a stop there makes sense too. Hell, Sheppard and McCowan seems ripe for development too.
I don't live in Scarborough, and won't use the line. It would be a miserable commute compared to alternative options, and that is before the ghastly transfer at Bloor-Yonge. But f*** it, if the province is going to pay for it, I am down. Let's get as many stops as we can.
Look at it this way. The development that would come surrounding the stops, and the rise in property values in the adjacent neighbourhood = more property taxes for the city as a whole.