I think you must be talking about CVE-2010-0232, it wasn't 90 days, it was more like 180. This was at a time when Microsoft refused to release kernel patches outside of service packs. I begged Microsoft at multiple in-person meetings at Redmond to reconsider and patch, they simply refused and said there were would be repercussions if I disobeyed.
After four months of negotiations, I told that I'm going to publish it whether a patch was available or not. This didn't have the effect I had hoped, they started threatening me instead. They called me and told me my career would be destroyed. In one particularly memorable call they told me that their PR and legal department only had two settings, "off and destroy" and (in a rather menacing tone) that they would "air my dirty laundry in public". I still don't know what that means.
I was shaken, but told them I'm still going ahead. They responded by calling everyone they knew at my employer demanding I was terminated.
There was a trivial mitigation, just disabling a very rarely used feature (vdm support for 16 bit applications). I made detailed documentation explaining how to enable the mitigation for every supported platform, and even made tutorial videos for Administrators on how to apply and deploy group policy settings.
I sent these detailed instructions to all the usual places that advisories are published. I included a test case so you could verify if the bug affected you and verify the mitigation was correctly deployed. As you can imagine, Microsoft were furious.
I know it's little comfort, but through some hard fought battles over the last decade we have reached the point that Microsoft can reluctantly patch critical kernel security bugs if given around three months notice. They still pull some dirty tricks to this day, you wouldn't believe some of the stories I could tell you, but those are war stories for sharing over beers :)
It sounds like your attackers compromised you with an outdated wordpress installation, then gained privileges with this vulnerability. I'm not sure I agree the blame here lies solely with me, but regardless, I would recommend subscribing to the announce lists for the software you're deploying. You could also monitor the major security lists for advisories related to the software you use. It's high volume and varies in quality, but you can usually identify the advisories that apply to you easily.
