This is no different to the College Board not accepting submissions from people who arrived by the subway or rode their bicycle. Or perhaps, used the wrong colored pen. Its at that level of absurdity.
Someone didn't bother doing basic testing. This is ironic because the system itself is a test submission system.
Personally I'd be wanting a full inquiry into this.
But the blame is still squarely on the College Board. They are a organisation that has actually failed in their core mission.
Apple etc shouldn't be the target of any anger. Some random website doesn't support image uploads. Thats the issue. The website should be more resilient. The College Board didn't do their homework. Perhaps they need to study harder and be more diligent? Attention to detail has consequences.