Earlier quoted context omitted.
These are also culturally dependent, and are in-group/out-group signals. Many people in Silicon Valley explicitly want to keep people who believe that business casual is more pleasing to the eye out of their social circles. It's a value judgment; to them, hoodies are more pleasing to the eye, and more comfortable, and they don't want people who believe otherwise in their companies.
Right, that's the point of the parent of this subthread. They (the hoodie-wearers) would probably insist that they don't judge based on dress or appearance, but they do, and maybe more harshly than the suit-wearers. It's just what people do. I grew up wearing suits to work, shaving every day, and wearing a short neat haircut. I don't as much anymore, but I don't wear hoodies with pizza sauce stains either, and I don'…
Some of those things are choices that matter and should impact your respect for someone else. Some are not, do not, and should not.
Personally, as a controls engineer who frequents messy manufacturing facilities, dressing in a suit gets in the way of getting work done. It subtly conveys "I'm too important to get my hands dirty, I'll leave the grunt work to the grunts." That kind of unwillingness to do whatever's required to get the job done is a point against those folks in my circles. I do understand that people who come to work in a suit may have different struggles vying for status and trying to send the right social signals in conference rooms, and I don't envy them those tasks - but please don't think less of me as a human because of what I choose to wear.