Thanks for going into detail regarding your "wildly unpopular" opinion although I suspect it isn't quite so unpopular outside California.
I can understand the value in certain circumstances of having a dress code or uniform, particularly with things like police, emergency, and military organisations. Soccer is also a good example. The goalkeepers have different uniforms and the captain wears an armband. So certainly uniforms can provide a functional purpose. But I can't quite see how wearing a tie fits into this.
I think that in a lot of environments clothing is used and has been used historically to signal superiority at a time when social rank was deeply tied to function. Consider in medieval times (and later) that it was normal for people to spend a third of their yearly income on clothing to distinguish themselves from the peasants, and there were all sorts of laws to make sure people dressed according to their position. Everyone knew their place and this order was enforced with violence.
So I don't think dressing up really helps to make visual signalling more egalitarian, if anything I think we're conditioned to equate appearance with ability. So I think we would do a whole lot better as a society if everyone made an effort to not judge or rank people according to visual characteristics. This is what makes and made places like HN, usenet, and BBS's so great. There is no visual signalling and all you have to go by are what people write. I believe that dressing down in tech is now sometimes a way for the tech industry to signal its superiority over other industries. It's a declaration of "we don't have to follow your primitive rules and customs anymore."
Western society has moved away from that level of formality except in the case of very special occasions. It's also perfectly normal to not shave everyday now. Both my father and grandfather shave nearly everyday because they've been conditioned to feel scruffy if they don't.
I can understand how it's important for a sales team to look sharp, because they can use people's conditioning against them to manipulate perception in order to influence customers. The nice suits and shoes are a tool. But I don't think this sort of image management has any positive value amongst a team of engineers working together to build something. What positive effect would wearing a suit and tie have over t-shirt and jeans? I ask that sincerely rather than rhetorically. And is that value high enough where it would be worthwhile for the corporation to absorb the monetary and time costs related to it rather than forcing the employee to absorb the costs?