Cities evolve. Some areas don't change, but stretches along main streets, especially those served by rapid transit, are bound to change. The provincial government has mandated that Toronto intensify, so this is exactly the type of location that makes perfect sense for that.
That said, I don't like seeing lovely old homes come down either, but their owners have a choice of whether or not to sell, and to whom. These properties were assembled over a long period, longer than a decade I think, and not by Daniels. Any developer would jump at the chance to redevelop assembled land like this, Daniels were the ones that got it.
In regards to "it's now only a matter of time before all of the original structures between Keele and High Park Blvd. - perhaps all the way west to Clendenan Ave, are bought up and demolished to make way for similar projects", well, most of the rest of Bloor Street is zoned as a neighbourhood on this stretch. This site had apartment neighbourhood zoning on it. It would not be easy for anything big to be approved in the neighbourhood zones.
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