Good advice, but hard to truly heed
>>Never use the same password and username combination on other sites, no matter how fringe.
Great advice but most users do not follow it because its a pain in the ass, and quite a number of people don't trust login manager software. Having a billion different usernames and passwords gets very confusing even to the most paranoid user. Having to try 100+ combinations and spend 15 minutes to do something that would otherwise take 10 seconds gets old quick. CorrectHorseBatteryStaple starts looking really good after doing things that way for awhile.
And I don't know if the author is implying this, but how are GitHub and Adobe fringe? Most people have used or use an Adobe product (though I don't believe you need an account at Adobe to download the piece of crashy garbage that is Flash or if someone absolutely insists on using Adobe Reader when there are plenty of alternatives of varying quality) and quite a number of developers, testers, package maintainers, designers, project managers and technical users use GitHub.