I would agree that right now there are more choices. I don’t entirely agree they’re inherently safer. Nor that this choice would have been available as a choice when the original decision was made. (At a time when the US was at the very least considered to be an ally to Europe)
If you think security of infrastructure has anything to do with PGP you’re misunderstanding what I mean. Self hosting mail for an organisation like the ICC would require multiple FTE’s. In the same vein that the current US administration is retaliating against them other rogue nations are constantly specifically targeting them. It’s already hard to deal with this without being specifically targeted and a couple times being targeted usually causes you to be compromised, dealing with it full time is almost impossible. Unless your team is monstrously big and securing your groupware is one of your core activities.
I’ve literally had jobs like this, and the idea that the average university that self hosts is more secure than Exchange Online is just plain wrong. I’m sure you can point to a couple of them that are safer of course, but they 'll be the exception.
Which is why I specifically phrased the part you didn’t quote in that specific way.
If you think you can set up mail infrastructure with on premise everything that is available to your not on premise workers safer than Microsoft, you will be spending a huge amount of money to do so.
It just turns out that the US has become a rogue state that alligns with the type of war criminals and dictators that the ICC wants to prosecute. I really don’t think anyone would have predicted this 10 to 15 years ago when this mail choice was made.
To be clear, I’m Belgian and in favour of abolishing monarchy. But as the news about her is unavoidable: she did study at the royal military academy as all in line for the throne have too. Then she went to Oxford for her Bachelor degree. Plan was to get the master at Harvard.
The justification is partly elitism for those schools, partly getting exposed to other environments, and partly getting too avoid being to isolated in Belgian schools where the attention would be inevitable and security too hard.