I liken it to the auto-industry in America during the 1950s. Back then, single income families could take long summer vacations to cabins they might even own. The jobs came with good benefits and company culture was important. It feels very similar.
People use terms like "get your hands dirty" to describe programming. Programmers are usually not encourage to wear button-down shirts, suits, etc.
You're basing this view on a very small subset of companies (startups). the vast majority of places where people work still expect professional dress above the level of t shirt + cargo shorts and flip flops.