Something that I wouldn't have guessed before we had tools that enabled instant communication is how long it would take new reputable information to reach some level of general awareness online. Often controversies and other ugly facts about well-known people or companies languish for years, largely outside the public eye though the smaller "dedicated"/insider community are often aware of it. Then eventually there's some sort of incident that attracts a lot of public attention, and all at once it's finally brought into broader public knowledge.

It must be a question of limited interest on the public's end.. and continually having to reevaluate your vague endorsement of some thing based on some random new controversy can quickly become tiresome. There's also the case of not wanting to bring down the wrath of a community by going public with ugly information about an individual who has a large and devoted following but that's a different situation.