Do you know the background behind this?
This past off-season, following a 5th season at the bottom of the league (and amid the on-field success of other recent expansion teams, some in their first year), MLSE decided it would be a good idea to... raise prices. Prices were already 4x as high as they were when the team played it's first game in 2006.
It didn't exactly work as planned. Crowds dressed in green for the last game of the season, symbolizing MLSE's greed, then a good chunk of season ticket holders proceeded to cancel their tickets. MLSE backtracked, but many season ticket holders never renewed.
Essentially, while the piss poor performance of the team (easily the worst team over the past 5 years in the MLS) certainly played a role, MLSE's own actions cost them here. They thought they could screw TFC fans out of their hard earned money the way they do with Leafs fans. It backfired on them, big time.
Yes, they do, to an extent. Certain season ticket holders, primarily those from pre-1999 (i.e. Maple Leaf Gardens), do not need to buy Raptors tickets. However, newer ones, particularly corporate interests do. This is a common practice with NBA and NHL teams with shared ownership.
The Raptors attendance probably would be hurting, as would be expected following a 60 loss season, but at the same time it wouldn't be as bad as you probably expect. The Raptors have a very solid fan base and have some of the highest local TV ratings in the league. They are one of the few clubs in the NBA that are actually profitable.
I'm curious what leads you to come to this assumption. The Jays sell out all the big games (Canada Day, Halladay's return, home opener), draw 30,000+ against big name teams, and have very respectable TV ratings. They have a lot of support, particularly among those who remember 1993.
It can only be "shameful" if people are expected to care for it.
In conclusion, no, I disagree entirely.
The support for 4 of the 5 Toronto teams are in the upper half of their respective leagues, despite their record of futility (unmatched in North America outside of Cleveland).
Furthermore, not only has Toronto never lost a major professional sports franchise, but aside from the Blue Jays (very) brief financial struggle in the early 21st century, they have never had a team even come close to relocating. If you want to talk about bad sports towns, first take a look at Vancouver (how's those Grizzles?), Calgary (garbage bags over the seats? really?), Edmonton (how many minutes till Houston?), Ottawa (bankrupt, in two different sports at that!), and Montreal (How 'bout them 'Spos?).
I'm sure the CFL relishes the thought of leaving a city of 2.7 million for one the size of Milton.