That's more likely a cultural thing, yes. I'm not talking about some random dude being picked at the last minute to interview someone and knowing nothing about them. Lots of times interviews take all day, with multiple interviewers or groups of interviewers coming in and out all day. Sometimes you grab someone you hadn't…
So a formally dressed candidate for an interview automatically has less experience? And for which interview, artist, programmer, HR, management? I doubt all of them dress the same way. What is the nature of the industry? It seems totally arbitrary to me unless you mean the more stereotypical game developer dress codes…