The problem the article discusses about needing to send lots of mail to qualify for these tools is because the systems don't scale infinitely - data storage still costs these firms money - and botnets mean basically every single IP on the internet will try to abuse your service at some point or another. So tracking deliverability data without any thresholding means tracking it for every connected machine in the world, which is hugely expensive, all to satisfy the tiny minority of people who feel passionately that they should run their own email server. The only possible justification for that would be recruiting related, but they don't have challenges recruiting.
If you have a few million of those or are part of our circle of buddies we just might cut you some slack. But otherwise, no matter that your vehicle performed fine just yesterday, it's up to us to change the rules at will and demand that you adapt.
Well what do you want for nothing? Randomly losing email is what the free email services do. That is hardly the fault of everyone else...
Oh, and I get more and more false positives in gmails spam folder as well, and since they're deleted after 30 days I now have one more 'inbox' to monitor.