I don't believe the AODA requires more than one entrance of any station to be accessible--correct me if I'm wrong, but I believe the majority of stations with more than one street level entrance only have (or are slated to have) one accessible entrance.
I also don't believe that it contains any provision such as this one I just made up: "you don't have to make more than one entrance of the station accessible, as long as each entrance is within 200 metres of an accessible entrance; if any entrance is more than 200 metres away from an accessible one, it must be made accessible".
Logically, at Spadina, it makes sense. The vast majority of the traffic at that station is undoubtedly for Line 2 and the 510. Additionally, while I do not know if these statistics are published, I strongly suspect that the vast majority of the surface level entry and exit to/from that station occurs at the entrances at Bloor and Spadina, and Bloor and Walmer; and also that the vast majority of the passengers for Line 1 there are transferring to/from Line 2 or the 510 or accessing those busier street level entrances/exits. I would be interested to know if there is an exact number of passengers daily/yearly/whatever who use the Kendal entrance--I would suspect it is a small number, on the order of 5% or less of the station's street-level traffic. So, having elevators from the Line 1 platform that enable a passenger to get to/from Line 2, the 510, and the Bloor-Spadina entrance, satisfies the vast majority of customer needs to the point that the station can be called accessible. And all that aside, I also expect that there are more daily Line 1/2 to/from 510 transfers, than there are surface level entries/exits, so Kendal might be in the 1% here, if not less.
I do sympathize with a hypothetical wheelchair-bound passenger living at or reasonably near Spadina and Kendal who wishes to get on Line 1. But realistically, it is probably a very, very small number of people. There are probably secondary entrances elsewhere in the system that might have hundreds of people with accessibility needs being forced to travel a total of maybe 150 or 200 metres to the nearest accessible entrance, per day; is it fair to say that, hypothetically, 5 people at Kendal being forced to go ~500 metres around, are suffering more than 100 or 200 people at some other station being forced to go 150-200 metres around? At any rate, while an interesting philosophical question, it would be a logistical and budgetary nightmare if the AODA required every entrance of every station to be accessible.
To provide some examples after curiosity got the better of me: using Google Maps' measure distance tool, at Yorkdale station with only the northern entrance being accessible and not the southern Ranee entrance, a passenger living at a house just west of the Ranee entrance could get there in 160 metres if they were on the south end of the train; if they were on the north end and had to use the northern exit, it takes 360 metres to get there, 200 metres longer. At St Clair W, to get from the main entrance to Heath St and Lower Village Gate it is 460m, vs. 160m if the Heath exit were accessible, a net +300m. From the south end of Queen station to the north, it is 190m. I strongly expect that some of these secondary entrances have more, potentially many more, passengers with accessibility needs than Kendal does.
