Perhaps OP should try avoiding recruiters and big sexy firms.
They report having a positive interview experience but were disappointed for being passed over.
"How is this possible — I have received emails from people all over the world, who praise and give me thanks for the work I’ve done on my open-source projects and tutorials (#humblebrag)"
Perhaps there was simply another qualified candidate? OP could use a little actual humility.
I do understand OPs point that the interview process can feel disconnected from the actual work. However writing software is only part of being a software engineer. Communication / working with others is also important. This is where attitude fits in. Being a professional isn't just about wearing the right clothes/etc.
Don't mean to beat up on the OP. Perhaps they would be a great employee and are feeling a little discouraged. Still, seems like all the praise for developers (e.g. being solicited by recruiters) has gone to their head.
