A similar kind of location was chosen for the new hospital in St. Catharines --
west side of the city in a developing area. Definitely not "central" but has the advantage of being accessible to the 406 and arterial roads.
This site looks fairly accessible to both the E.C. Row and 401, Lauzon Parkway, Walker... Howard Ave. a bit farther. Perhaps that's the reasoning it was chosen.
Also, is growth planned to happen in south Windsor and the adjacent parts of Essex county? Or the town of Essex?
That all said, if a facility like this goes up in Hamilton, I would not want it to go
here or
here -- neither site is central, even to the upper part of the city (locally known as "the mountain") but both have highway access and are in parts of the urban area where lots of growth is planned.