Usually, when someone is advocating moving to a newer market, they're anticipating growth. My guess is that those wanting to move to KC aren't anticipating as strong early returns as they'd see in Pittsburgh, but, with a wide open sports market and a rising team, anticipate the ability to see larger growth. The prospect of a free arena then augments whatever value they get.
As for the Southern Ontario issue, again, there's much less issues with a team in Kitchener-Waterloo, than there is in Hamilton, and the former is Balsillie's home base. If we're arguing pure revenue potential of markets, KW is right up there. It would be surviving with a complete privately funded arena (as arena subsidies will not fly up here right now). But, pure revenue potential is not what drives where teams go, it's cash flow potential. That's why markets that throw a lot of subsidization towards their teams get franchises.
BTW, your math is wonky. You can't discount cash flows to present day value, and then amortize it back over the lifespan again like that. Either it's present day values (roughly $40M NPV), or its per annum values ($2.9M per year).