I think there is an interesting case study on stadiums situated more northerly (Seattle, Minneapolis) or at similar latitude (Milwaukee, Boston, Detroit, Chicago x2, Cleveland) to Toronto, vis a vis market demographics. Of those 8 stadiums, only 2 (25%) have retractable roofs (Seattle, Milwaukee). Of the remaining 6; 2 (25%) were built prior to the era of domed stadiums (Boston, Chicago); 2 (25%) were planned/built in and around the same time as Rogers Centre was built (Chicago, Cleveland) and it is likely that the concept of a retractable roof wasn't even a consideration at that time; that leaves the last 2 (25%) that have built new stadiums during the modern era of stadium construction, but did not build a retractable roof (Minneapolis, Detroit); I would argue that Detroit as a market is a traditional baseball market that has a long history (1912 - 1999) of attending baseball games outdoors in all weather. Only the Twins who had played in a domed stadium for nearly 30 years chose to build fully outdoor stadium though the reasoning was financial (none of the Twins, or municipal/regional governments were willing to foot the extra ~$100 million to add a retractable roof), not aesthetics.
I think there is something to be said for the local market and the appetite (or willingness) to watch baseball out in the cold (but dry) spring weather. Cities like Detriot, Chicago, and Boston have over 100 years of having MLB baseball to watch and knowledge of the unpredictable nature of weather. Toronto on the other hand, despite the long history of minor league baseball in town, does not have the history of baseball in town like the above noted cities do. In a way the market has been spoiled by Rogers Centre, I used to work at the Rogers Centre and I can't tell you how many times people would complain to me about the roof being open when the weather outside is clear but cool "ugghhh it's cold can't you close the roof", "Ummm sir/ma'am you had to walk OUTSIDE to get into the stadium. Shouldn't you have dressed for the weather?" I don't think Torontonian's are soft either because TFC fans have braved weather in early March and early December to support their club. It's just that Toronto as a market is only one of 10 cities in North America to have a franchise in 4 major pro sports (Hockey/NHL, Baseball/MLB, Basketball/NBA, Football/CFL, Soccer/MLS) and baseball is probably in a dead heat with basketball as second most popular team. The competition for the discretionary sports dollar is pretty fierce and that's why teams should be doing as much as possible to remove any reason to not attend a game (poor weather). As long as Rogers is footing the bill for the stadium I do think a retractable roof is necessary, however...
That was before the roof upgrade, when they couldn’t move it below 10 degrees. The risk was having everything seize up due to metal contraction and get the roof permanently stuck half-closed.
A number of games each year were warm enough for an open roof, but they had to go off the expected temperature when closing it following extra innings.
It's important to remember that the stadium was designed and built as a domed stadium that can be open when the weather is nice, which is vastly different from an open air stadium that can close during inclement weather. I remember working a game when a rain storm came in unexpectedly and they couldn't close the roof in time. It poured in the stadium for nearly 20 minutes, and, because there was no drainage in the seating bowl the front row of the 200 and 500 levels was just a river an inch and a half deep of rain, and ballpark related garbage (drink cups, beer, pop, popcorn, hot dogs, etc, etc) it was disgusting.