Yea, but if they can't get a healthy return they won't do the project, and it wouldn't get built, with developers continuing to build what is profitable - sprawl oriented properties on the edge of the city.
I'm not sure if this money is needed to make that return, but given that nobody has built an office building in MCC for 30 years, I suspect it is.
I get the idea behind these incentives, and honestly, They make a lot of sense to encourage the type of growth the municipality wants to see.
Toronto had IMIT grants for downtown office for decades to encourage downtown employment growth when the suburbs were exploding with office development in the 1980's and 1990's, and held onto that incentive a bit too long I think (they only got rid of it recently), but areas like Vaughan, Mississauga, Hamilton, etc. need to make it financially easy for employers to locate in urban locations, at least until a critical mass is reached whereby new construction can pencil out on it's own.