I'm sorry, which part of 'this was not a security vulnerability' were you having trouble understanding?
It has actually been mentioned how this was exploited on sm.org: someone uploaded a theme with extra files in it, one of which had nasty code in it. There are other routes to doing something similar - namely the theme editing functionality - but the point stands: this was a compromised account by way of an admin being on another site with the same password and the password compromised there.
The real question I would level at the SM people at this point is why basic security practices were not carried out with respect to files not being made read-only after modifications were carried out. But that's still not a security issue in the software, that's a fault of the underlying operating system configuration and a lack of knowledge and understanding from the people who organise such things. I understand there is some confusion as to what must remain writable for standard functionality.
There are, to the best of my knowledge, no vulnerabilities that have been reported and not been investigated. That is not to say that all reports were valid, or that all reports had an exploit that actually needed immediately patching; the most recent vulnerability, for example, actively requires an admin account to actually exploit it. If you already have an admin account, the potential for mischief - as seen - is already demonstrable and thus while there is a bug to fix, it is not really a legitimate vulnerability if it already requires all the keys to the kingdom to be able to exploit it in the first place.
If you can provide a report that you believe has not been taken seriously, please do contact me and I will investigate and take whatever action needs to be taken (including providing patches to SMF if necessary, it's not like we've never discussed vulnerabilities with them before now). I am well aware such claims have been made - but like every time this has been raised, we always ask for reports or indeed anything to back up this bluster and nothing is ever forthcoming. Provide me with something to work on and I'll look at it. Provide me with bluster and the only thing I can conclude is that you're just trolling and shit-stirring.
In any case, haven't you since been banned from sm.org?