Do you have a source for that? Looks like MS have released a number of patches for these exploits and so have other software vendors so I'm not sure what your claim is based on.
According to ArsTechnica, the Shadow Brokers' exploits were patched (silently) back in March. This suggests that no fully patched system should be vulnerable, which doesn't jibe with what some security researchers were claiming.
Mucrosoft patched a lot of the vulnerabilities within the last several months. That doesn't mean that they weren't serious vulnerabilities (i.e. the scope of the exploit) or that they weren't actively used (since the exploits could have been used from the time they were found by hackers to the time they were patched).
Also, I see a lot of green accounts in this thread...
I follow one of the people who was first to test these exploits out. They're not actually an amateur, but they did forget to patch their test VMs. Just like a lot of the other people who replicated the results.
The thing to be fair about there is that you can install Windows 2012 R2 in a VM in about 15 minutes, but if you want to apply all updates, you could be sitting there for hours.
I built and updated two servers on spinning rust last week and it took six separate reboot cycles and nine total hours.
It probably isn't about "forgetting", as much as considering that there was indication patches were relevant and you wanted to start this research today.
Edit: It's easy to call people "amateurs" in hindsight, and not necessarily fair.