So what is this solution that everyone is aware of except for the people at the TTC?
Of course the 501 is going to have route management issues - it's an extremely long route and it's a streetcar, which means delays pile on a lot more than they would on a bus route.
You're buying the typical BS the TTC like to use as an excuse for not running adequate service. The solution is plain and simply better line management.
Line Management is practically non-existent at the TTC, despite what they try and tell commuters. The 501 has continuously run into numerous problems after the route split on both the Humber-Lake Shore branch, sand the Humber-Neville Park branch.
@interchange42 pointed out one of the problems with the missed connections at Humber Loop and that's just one of many issues the route has. Other issues include: bunching west of Humber Loop where the traffic doesn't and should've have an impact on operations, and regular gaps in service which resulting in 20+ mins wait times.
If we look back a few months ago when buses replaced streetcars from Sunnyside Loop to Long Branch, there were frequent complaints of -brace yourself for it- buses bunching and regular service gaps of 20-30 mins. Again, this is along the section of the route where traffic shouldnt have an impact on operations. During that same period of time at night, it was very common to have waits of close to an hour just to catch the connecting 501L bus from Ellis that would take customers the rest of the way to Long Branch.
The common theme here is that no matter if it is a streetcar or bus, the TTC has issues properly managing service even when a route a split and the operations are in large part independent of one another. I wont even get into the other long routes that the TTC operates, because in general the longer the route, the more pathetic the line management is. The exception to that rule are the few routes that the TTC regularly monitors (ie: 29 Dufferin, and 7 Bathurst).
Now it will be interesting to see if the new VISION system will rectify a lot of these issues since operators will finally have a way to communicate with each other, and they will know if there are issues with other parts of the system. Transit control will also be able to keep in contract with operators of any specific route, compared to the antique TRUMP system which is incapable of doing all that. It should be noted that there have been rumors that the TTC will be moving route management of most bus routes from their respective garages, over to transit control at Hillcrest so it remains to see how this will impact operations when and if it happens.