I don't know how reading that report you can objectively single it down purely to airspace... While I'm sure controlled airspace would have been a significant help, not following the missed approach tracking and just generally maboing flight below lower safe in IMC is never going to end well. All the other aircraft managed fine.
It's weird to me that there seems to be a chorus on Pprune of not having overly expensive regulations on safety if it's not worth the perceived cost to operators (aircraft owners), but the same matrix doesn't apply to controlled airspace.