Why naturally jump to the conclusion that Comcast (Who, while many will criticize, probably know vaguely what they're doing) is broken before researching /why/

Why naturally jump to the conclusion that Comcast (Who, while many will criticize, probably know vaguely what they're doing) is broken before researching /why/ it wasn't working? DNS isn't the most simple thing in the world, and things like this can catch a lot of people out, particularly if your DNS host doesn't tell you root level CNAMEs are not recommended, but automatically assuming someone else must be doing something wrong, just because you think it should be working, is frankly stupid. It's the sort of thing I'd expect from TheDailyWTF or /r/talesfromtechsupport, not a reader of Hacker News.