This is exactly the point I'm trying to make.
Why do Bayview and Leslie have just one bus route feeding them? Why do Broadview, Chester and Pape have multiple bus routes feeding them despite being so close to each other?
Density.
The subway works in that area because it's exactly the kind of area subways were designed for. It's dense and walkable.
And let's not forget, even with a ridiculous bus terminal being built to divert all buses directly to the SSE station, the ridership is still relatively negligible for a station that's 6km from the next subway stop.
The density argument, while although partially true, is extremely convoluted and not a good metric to measure future TTC ridership on its own. Here's the proof:
Yes, there is a general trend that with an increase in density, ridership increases. However, your correlation coefficient is 0.095, which is an extremely weak correlation between density and ridership. You cannot argue that density alone is the only factor that influences subway ridership, especially in the suburbs.
(Ignore the circles, they are biased)
Here we see that density around subway stations, especially suburban stations like Kipling, Warden, Kennedy, Downsview, Wilson, York Mills, Lawrence, Yorkdale, Lawrence West, Jane, Islington, Royal York, etc. These are all stations that are considered to be in the suburbs yet have excellent ridership; Warden has a better ridership than most stations on the Bloor Danforth line, yet there is basically no density. All the terminal stations with the exception of Finch and Don Mills have basically no density whatsoever, and they are the highest used stations in the system. Likewise, even in downtown where stations are in dense areas, ridership is basically no existent. Take Spadina, you'd think it'd have one of the best ridership in the system, but it is actually one of the worst performing stations downtown averaging only about 13,000 riders on the Yonge portion per day. Considering that it's a transfer station for both the 510 LRT and the Bloor Danforth subway, it's combined ridership of around 40,000 is really closer to 5-10,000 for people genuinely getting on and off at the station. There are others; Museum has one of the highest downtown densities, yet has the worst downtown ridership; it's almost as bad as Leslie and is worse than Bayview stations.
This is completely untrue. Ridership for the Sheppard Line is poor by international subway standards.
Not only is it poor, such a subway line would never have been built while there are still major areas of density unserved/underserved by subway stations. If Toronto was a European or Asian city, I'm quite sure a DRL and a line along King or Queen (or perhaps both) would've been in the pipeline long before Sheppard.
The stops you mention completely ignore context too.
Chester had 7,700 riders a day in 2015, that's true. But what about the stations before and after?
Broadview - 33,460
Chester - 7,700
Pape - 28,710
Donlands - 11,500
TOTAL: 81,370 over 1.9km
According to the same 2015 TTC stats, the Sheppard Line handles just 49,070 riders on a 5.6 km line.
You can cherry pick specific stations on the Bloor Line that don't have high ridership, but you're missing the point entirely. The Sheppard Line has three stations with ridership below 9,000. The entire Bloor Line has the same number (four if you want to include those under 10,000).
The entire Sheppard Line is poorly used.
Continuing to make mistakes such as the Sheppard Line are quite indefensible when there are major needs to address. The SSE is a much, much larger mistake than the Sheppard Line - it's probably the worst proposed expansion in TTC history.
Again, it is true, I did the math. If we assume that 50,000 people use the Sheppard line every weekday (t0 factor in the bare minimum for weekends), and assume there are about 300 weekdays in a year, we get 15 million yearly riders. Per kilometer, that's 2.73 million annually per kilometer. We know that the ridership of the Sheppard line is better than almost every metro system in the US, with the exception of New York and there's not enough information on Montreal. Let's just take London's underground in its entirety, considered to be one of the busiest in the world. 1.340 billion annual riders. Divided by 300, and then by 402 (length of their system), we find an average of 11,111 passengers per kilometer. Compared to Sheppard's 9,100 per kilometer, London's averages about 2000 more passengers per kilometer per day on the high end of the spectrum. On the high end of the spectrum, where we assume ridership on Sheppard during the weekend is the same as a weekday, then London's ridership per km drops to 9, 132 people per day on the low end of the spectrum, basically the same to Sheppard. When you consider the fact that all of London's underground goes through much denser areas than Sheppard (except parts of the Metropolitan Line), the ridership levels are quite incredible. Plenty of other European cities go through this, the exceptions of the ones I checked being Prague and Moscow. How about in Asia? It's a little different considering that the cities were built with mass transit in mind an not the car, like here in North America, however, there are still examples of where daily ridership per kilometer is higher on the sheppard line than entire subway lines. Take Nanjing's Metro, 832 million people use their 347km system annually. Assuming there are 300 weekdays, 7,992 people use the subway per kilometer. Daegu South Korea? 163 million annual passengers on 81 km of track. That comes to 6,708 passengers per kilometer. The numbers don't lie. Kunming China? Hamburg Germany? Barcelona Spain? All these systems have ridership levels with fewer people per kilometer than the Sheppard subway. Also, Bayview's ridership, statistically, is over 9000 ppd, so that was a flat-out lie (8990 people in 2015, 9030, 9330, 9380, 9390, 9030 for the years before 2015). When you look at the Yonge line between St Clair and Bloor yonge, there are two stations with a ridership of less than 6000 each (I put Rosedale's lower because it has a general trend of lower ridership; it has steadily declined from ~8000 in 2011, 7000 in 2011-2013 (years of changing timeframe for station counting), and 6,250 in 2014. Summerhill has been stagnant). Yes, it's not as bad as the section between Bayview and don mills, however, it's right next to downtown. As I said before, they built the station at Bessarion for future development, if they were fcussing on bus connections (which I think has much higher merit), they shouldn't have built it at all.