What is wrong with the advice? You are saying nobody was wearing a suit. I said dress a step up (for the interview). Sr. Management in graphic tees? Wear a polo shirt. Or sport your best conversation-starter graphic tee. And if the CEO wears a tee-shirt and all the rest are in some other category of dress, base your interview attire based on everyone else.
Mmm... because I'd prefer the approach of Donald Knuth: wear dashiki to special events (like interviews)? I don't mean I endorse West-African style literally. Just either wear something that says something about you, if you are into that, or be neutral and approachable. No need to plus one anyone.
