Ok, I have one to add myself: 6) We used to have many small outages at different websites. Now, with so many things that once were separate small sites aggreg

Ok, I have one to add myself: 6) We used to have many small outages at different websites. Now, with so many things that once were separate small sites aggregated on sites like FB, Twitter, Reddit, etc we have a few large sites, so we have aggregated the failures along with that. The failure rate, by this theory, is the same, but we have replaced "many small failures" with "periodic wide-spread failures, big enough to make headlines". Turning many small problems into a few bigger ones. Just another hypothesis.