"(too dangerous for weekend warriors to operate)."
I know in many jobs in the military the reserve and guard components have been superior to their active duty counter parts (in the past at least), in jobs like pilots, armor, medical etc., in some jobs like civil affairs just about everybody is National Guard.
In the 80s I read about a National Guard armor unit, it explained how the crew members had served in the same units, for the same time, as the young men currently on active duty, but that the guard now had 5 or ten years or more with their current guard team, therefore blowing away the young active duty guys in exercises.
In the Air National Guard pilots would do their 4 or 6 years active and then with another 15 years in the guard, defeat their younger, less experienced active duty competition.
The problem with reserve subs would be how to deploy and maintain a sub for 2 day exercises and 2 weeks in the summer.
Among the most difficult units to keep at a level with the active duty is Infantry, Navy Seals, Special Forces and such, it takes a lot of commitment by it's members.
The real problem is that any reserve force of submarines would be nuclear powered ones... In my day aboard the boats (1960s-70s) we constantly drilled on nuclear safety procedures so I cannot envision a reserve submarine where, for one weekend out of a month, Sailors would be operating nuclear power plants. The old diesel boats, too, were accidents waiting to happen. All it would take is one false reading of the ballast control panel "green board" and a tragedy would occur (that's essentially what happened to the old Squalus in the late 1930s and perhaps the Scorpion in the 1960s). The environment that submarines operate in, like the environment that airplanes operate in, is extremely unforgiving.