LRT is not needed on Hurontario any more than it is needed on Ossington Ave.
Ossington Ave does not bisect 3 GO train routes like Hurontario does.
Consider that not too long after GO RER, electricifation will probably extend to Brampton from Bramalea. So it would be a major connector to a route that had 2-way all-day 15-min service, including an airport station. That's why Hurontario won -- it completes connections to 3 GO stations.
Consider that thanks to the LRT, Brampton is going to eventually have a quick airport connection (e.g. the proposed RER Woodbine/Pearson station -- which now shows up in one of the SmartTrack alternate routes too -- and when RER is extended to Bramalea -- when the freight railroad ownership roadblock is solved). Also, when Kitchener 2-way service begins someday (long-term plan)
we can finally have a practical Mississauga-Kitchener daily rapid transit commute (both directions), not too different from an Oshawa-to-Toronto commute, or Burlington-to-Toronto commute. Hurontario is a key LRT route that has a bias factor that goes beyond the passenger count.
Although there seems to be other better funding for the Hurontario, one has to realize that we're projecting 2025 passenger traffic, not for 2010 passenger traffic. Hurontario is pretty high up there, when you account for the gridding/expansion potential of the GTHA transit network.
This easily increases Hurontario traffic through Brampton, especially if the LRT extends a little bit northwards, too.
We're looking at 2025 projected ridership, not 2010.