Why is it strange that property owners would want private green space, and that developers would provide it for them? The beauty of generous sites like this is that architects can design buildings that float in the air and provide views of the lake below or between them - for the delight of those who stand to the north of the site and mistake Queen's Quay for the genuine waterfront promenade to the south. Toronto is famously a city by a lake, and the point at which the city meets the lake is a defining space quite different from the Quay.
Don't create a straw man - I didn't say that it's strange for people to want private space and it's strange for developers to give it to them.
On many projects that I have worked on, for example, the developers want
everything to be accessible indoors. Owners will have to go outside to bring their garbage to the chute? Unconscionable! Needs a glass walkway! Meanwhile, said owners will go outside multiple times throughout the day, even in winter, going about their regular business in the city. You end up creating all sorts of measures to avoid these perceived negatives and the buildings+circulation suffer as a result.
They also assume that if there aren't gates and fences somewhere, a space will automatically become over-run with the freeloading public who don't own the space. Nevermind the fact that if you don't
draw people into a courtyard space, they won't actually go there... and nevermind that on a site like Waterlink's, you don't exactly have throngs of people using the site as a shortcut to get to the other side of the site (and therefore since there's no reason to go there, most people won't). Many developments, as a result, end up with segregated "open space" that is under-used because it isn't comfortable... it's surrounded by fences, it's only accessible via a keyed door from inside the building, it's not adjacent to a street, or any other number of situations. You can't just "end up" there, you have to take a very purposeful route... it's "private public" space, rather than "public private" space. there's an important distinction there that I can elaborate on if needed, but the point is that the developers have ideas about how buildings should work that don't necessarily reflect good urban design, and *that* is what creates a lot of the situations we see on the waterfront.
On Pier 27 specifically, they are no longer public because the developer wanted these long enclosed walkways connecting the lobbies of the building... a simple move that has all kinds of bad consequences, including cutting off the siteline to the water. You can give people terraces, put a public space between them, and come back later to mitigate through-traffic
if it is a problem. But most developers imagine the problems that may never come to fruition, and force the architects to design the solution in advance.