While the idea is still very much in its infancy, it's one that, at least on the surface, seems rational. Since only about half of OC Transpo's operating costs are funded by fares (the other half coming from the tax base), a rider from Kemptville is paying about half as much as one from inside the city line.
By that rationale, though, tourists are also paying far less than the 'true cost' of OC Transpo rides they might be taking, and we're not about to start asking them to top-up their fares. It's always going to be a tricky line to walk when certain people pay for (part of) a service aren't the only ones who might use it.
One possible benefit of the move, according to CTV, would be unclogging the Park'N'Ride lots through the city. Which might be true, but even if it does, that just means more cars driving into the city, and fewer people taking the bus; is that really a positive outcome, overall?
As said above, it's still all hypothetical, and in the investigative stage; it won't even be considered until next year's budget. Who knows, perhaps staff will come up with an arrangement that brings in some extra income to offset the discrepancy, but still doesn't overly inconvenience out-of-town riders; that would be the ideal situation, realistically. But it will be interesting to see if the idea gets much political traction.