how many bands these days play entirely with instruments that weren't even invented until the 1980s? (ok skrillex)
how old is a drum kit
how old is a guitar
how old is the human voice
and they don't count as retro?
i think the difference is that none of those things have ever been a novelty, at least not in the last 100 years
chipmusic hasn't been a novelty for 30 years at least.