My two cents, with perhaps a little flippancy and trying to look at it from a holistic / political / PM&C POV.
RAN requirements are basically for a boat that can conduct the same missions as an SSN but without actually having nuclear power, so what better than an SSN design without nuclear power?
Steel industry is in trouble due to cheap Chinese steel being dumped globally (I suspect that part the reason that Mitsubishi was carrying on so much about their special steels is because the global glut it hurting them too). Option F not only throws the local steel industry a lifeline but will likely see the tax payer investing in much needed modernization as well as an on going, captive market. Protection for a vulnerable industry, made more vulnerable by a collection of FTAs, without being seen to actual protectionism.
A series of recent reviews have established that ASC are actually extremely capable when not constrained by inadequate funding and micromanagement by a technically naive, risk adverse (that incidentally had no real understanding of the risk) executive (i.e. successive governments and in particular some of the board members they have inflicted upon the organisation). Since the Coles review and the associated loosening of the shackles plus more appropriate and sustainable funding levels, ASC have demonstrated massively improved performance, including innovative solutions to persistent problems. Combined with the clear air gained by the removal of defmin Johnston it has been seen by Cabinet that ASC is a strategic asset worth saving and, though too late to reverse the decision to scrap the local design of the replacement submarine, we are well and truly capable of partnering with an established designer and providing what the RAN needs.
Lessons learned from not only Collins and AWD, but also MU90, Tiger, MRH90 and other projects, include that Australian industry can and has stepped up to complete major, complex work that the designer/vendor/partner has not done/completed or has screwed up. The message may have actually gotten through that instead of blaming and criticising local industry and capability for cost and schedule slips, more often than not caused by issues beyond their control, that they have consistently managed to recover the situation and provide the required capability against adversity and as such should be listened to and trusted more.
The big one is, if we actually understand the risks involved, plan and provide adequate funding, mitigation and resources, realistic budget and schedules can be achieved. Further more, as seen with the tech gf mentioned and other examples such as Australia's integration of Hellfire on Tiger, we can actually export the fruits of this work.
Not wanting to get into a political discussion, but I can see the submarine decision as a change in the substance of the government since the change in PM. We appear to have gone from a negative stance that Australians (with the exception of a wealthy few) are affable but lazy and not too smart, to one where we believe that we can do things as well as anyone else when given a fair chance. A change in that we are now looking to partner in a risky design and build instead of killing sovereign capability and buying a turnkey option from overseas.
Nothing is set in stone, a change in government or even just in PM could see a complete change of direction with canoes entering the fray again, reputations of people and organisations trashed and the usual suspects trying to offshore everything again, but for now I am going to be positive. I am going to look at the challenges of option F as being a vote of confidence in our capability to overcome them and make it work, i.e. an Australianised combat system of which BYG is just a component as has been successfully done on AWD with AEGIS. Australian innovations developed for Collins being evolved and implemented on Shortfin (something that was far less likely on Soryu+). As I am choosing to see it Soryu+ was the F100, Shortfin the Baby Burke, fingers crossed we can make it work and that, being a coalition government baby now, it can avoid the death by rhetoric of the Collins.