The idea is that it demonstrates respect for the institution: "I took the extra trouble to dress up fancy to come here." The definitions of "fancy" and "formal" in institutional settings change over time, but they change more slowly there than they do in the culture at large. So it's not uncommon to see people wearing clothes that the general culture would consider outmoded or obsolete in these contexts.
Here's an example. The top hat (http://en.wikipedia.org/wiki/Top_hat) was a standard part of formal dress in the latter part of the 19th century, but it had mostly fallen out of everyday use by the mid-1910s. Diplomats and statesmen kept on wearing them at official occasions, though, all the way into the 1950s (see http://en.wikipedia.org/wiki/Top_hat#20th_century).
Why? Because they had become part of the definition of "what you wear to an occasion of state." That type of distinction, once reached, takes a long time to fall away; no diplomat wants to be the first person to cause offense by ditching the top hat. So it had to be dead in the everyday culture for decades before leaders felt safe enough to stop wearing it.
Suits are probably on a similar trajectory: once an item of everyday wear; now mostly a way to signal that you're on your way to a Serious Event (like a wedding or funeral or meeting with a head of state); eventually just something people wear to Serious Events only because that's what you wear to Serious Events; then finally (long after they became obsolete everywhere else) left behind even for that.
> The idea is that it demonstrates respect for the institution:
You know what grown-ups see as demonstrating respect for an institution? Devoting a substantial portion of your waking hours to performing quality work on behalf of the institution.
If you prefer ritual displays of conformance as a mark of respect, that's a choice with consequences, and either not recognizing or preferring those consequences is not a sign of being "grown-up".
This seems simplistic. Ritual is an incredibly important part of human life.
I say this as a non-conformist in many areas. But I conform in many that bring me no pleasure. For instance, I don't meet clients in shorts or pajamas, though either would be more comfortable.
What's the difference between that rule and wearing a suit at the White House?
Respect doesn't have to be an exclusive either/or between ritual and quality work.
And either way, if the "software engineering dress code" becomes shorts and sandals and you'd be looked down on for wearing a shirt and tie, well, you're still a conformist. You're just selling out to a different rule book.
I was a non-conformist in high school and much of my undergrad, but you'd probably never have known it, as I wore things which were comfortable (and happened to be inoffensive) rather than going out of my way to dress in the same uncomfortable things that all the other "non-conformists" wore to show society they didn't care, man.
You know that it can demonstrate respect for an institution that you're outside of, as well? Good luck testifying in court wearing sweat pants and a tank top.
Here's an example. The top hat (http://en.wikipedia.org/wiki/Top_hat) was a standard part of formal dress in the latter part of the 19th century, but it had mostly fallen out of everyday use by the mid-1910s. Diplomats and statesmen kept on wearing them at official occasions, though, all the way into the 1950s (see http://en.wikipedia.org/wiki/Top_hat#20th_century).
Why? Because they had become part of the definition of "what you wear to an occasion of state." That type of distinction, once reached, takes a long time to fall away; no diplomat wants to be the first person to cause offense by ditching the top hat. So it had to be dead in the everyday culture for decades before leaders felt safe enough to stop wearing it.
Suits are probably on a similar trajectory: once an item of everyday wear; now mostly a way to signal that you're on your way to a Serious Event (like a wedding or funeral or meeting with a head of state); eventually just something people wear to Serious Events only because that's what you wear to Serious Events; then finally (long after they became obsolete everywhere else) left behind even for that.