"The first round had four interviewers in the room. It was an open-ended discussion about me, my accomplishments, my projects. To be honest, I was not prepared for this interview format, so my presentation was probably all over the place"

A professional programmer, the one hired by a company to work alongside other professionals - as opposed to one working by themselves on small projects - is capable of presenting previous experiences and applying them to new problems. Unless you want to be put in the basement and handed small chunks of work to solve. It's about how you mentor juniors, resolve disagreements on how to proceed, deal with set backs and changing requirements.

Given the whole post is about how terrible the interviewing process is the above quote is the most telling, and backs up the GPs point - not being prepared to have a conversation about your previous experience when interviewing for a job is pretty bad.