On the other hand, I guess most people probably aren't typing the url out anyway but googling it instead.
"BURRITO.CONSULTING"
I'm going to think, "uhhh, is that a website? Well, I recognize .consulting as a TLD. I guess it must be. But that's weird..."
but then if i see the same sign
"WWW.BURRITO.CONSULTING"
I'm going to think: "Well that's definitely somebody's website, but what a weird and anachronistic way of printing it, and why is it using one of those new long generic TLDs anyways..."
People outside tech generally don't realise that domain.tld and www.domain.tld are two separate hostnames, and adding www. makes it much more recognizable to the general public.
So for subdomain.burrito.com, we redirect the wwww.subdomain.burrito.com
People are just so used to it.
1. Avoiding the relatively common pairing of {a host whose IP address changes without warning so you need to CNAME it; a DNS provider that doesn't offer CNAME flattening a.k.a. ALIAS a.k.a. ANAME}.
2. Scoping session cookies so user agents don't also send them to your subdomains.
And maybe even more stuff I'm forgetting.