It boils down to ridership numbers with the Lakeshore being #1. If the numbers are not there to justify 30 minutes, then it has to be hourly regardless you want more.
Service should start earlier on all lines as there are things going on on the weekend that you may miss something with service starting later, especially if you are taking part in it.
Until there are shorter trains for weekend with good ridership, it is the cost of the crews as well the equipment to put more service on line for a small number of riders.
We have to ask the question, why is Lakeshore #1. Certainly helps that it gets by far the most service along the network, with 50+ years to develop that ridership.
If we were to take LSW service levels and put it on every line along the system, I don't see how Kitchener doesn't get far and away the most ridership. The destinations along the line, including KW with WLU and UW, Guelph having a major university as well, ALL OF BRAMPTON, the West Toronto stations, it could really justify 15 minute service, at least to Mount Pleasant service all day, everyday, starting today.
Anyone who has gotten on a train at Mount Pleasant, Brampton Innovation District, Bramalea knows. Speaking of Bramalea, the way people move through the station during peak times is a marvel. The bus connections at that station are next level. Massive throughfare. How about all that discourse about those packed 30 and 30As skipping everything along the line from Bramalea except Kitchener, where 4 buses an hour are sometimes not enough.
Anyways, the point is, for the Kitchener Line, and likely other lines, the reason there is lower ridership is due to the level of service, the lower ridership should not justify lesser service. Corridor ownership, costs and staffing aside. If we wait for the "until" when the shorter trains for the weekend come, we may have to wait forever, ridership won't come unless service comes with it.
Anyways it is clear that I am passionate about the Kitchener Line and it's absolutely monumental potential. If deployed correctly, it could solve so many issues on the 401, and may someday in the far future host high speed rail. Though I'm not holding my breath for that.