Well, from a more practical standpoint - Redpath is providing jobs in the area, and it does need a harbour site. Given that it's no longer using the rail spur, working with WT on the QQ redo, with a relatively small impact on area residents (than say, the hundreds of vehicles they drive?), I don't see why it is any less legit on the waterfront than say those living by the waterfront condos, who did their darnest to keep WT from building the pedestrian bridges along the boardwalk. If there is something one should bitch about it is the latter.
AoD
Right, yeah, this is a more reasonable and cogent argument, by my lights. My problem with the heritage-site arguments is that, as has just been remarked above, it seems to be mainly an argument from age and historical significance, as, barring reasonable differences in taste, I just don't think the factory beautifies the area (unless, yes, you think that historical significance is a function of beautification, to which I respond: then let's keep the Greyhound depot at Front and Sherbourne, and so on [and also: how historical is historical? 20 years? 30?]).
At the same time, I understand that heritage preservation isn't just for the 'nice' buildings. Some can be historically significant while being quite ugly, and that sometimes is enough to preserve it. But then I think: well, historical significance is generally something that tells a unique story about this area, something that sticks out in Toronto, that no other city has, and that is recognizable by others as a historical site precisely because it's unique to the area. I personally don't think the RedPath factory passes muster here; sure, it's unique in that it's
the RedPath factory, but it's not unique in the sense that Fort York is unique, or even the CN tower is. So in this sense, the RedPath factory is historical but not significant.
To respond directly to AoD's economic argument, I think focusing on the economics invites simpler analysis about mixed-use development. And for the same reason that I don't think any of us would want the RedPath move into the lot on Wellesley b/t Yonge and Church--shipping logistics put aside for a moment--maybe many of 'us' (present company obviously excluded) wouldn't want it down on the Quay. In other words, economic analysis allows more easily for thinking about the operation in terms of zoning, and we typically leave primary industry like this to zones in which other primary industries operate. So, basically, if we analyze it economically, I think the conclusion follows that either it should be moved to a zone where similar operations exist, or we should rethink developing the Quay into a residential/commercial zone.