why not just omit it altogether? an have foreward slash like /hubski.com
http means that we are using the server for accessing HTML files - normal web browsing. We can also use other protocols like ftp (used for transferring files), smtp (outgoing email), imap(incoming email), etc. Sure, when we're using a web browser we can usually assume that it's http (or https) but this is not always the case. As for the 'www.', typically we just redirect the 'http://www.hubski.com address to 'http://hubski.com (or vice versa), but we don't have to. You could make the addresses point to different websites - although why you would want to do that is a mystery to me. BTW, having a leading / such as in "/hubski.com" will often make the browser think you're looking up a file.
The HTTP has an important meaning - it says the protocol you're using. Other options might be HTTPS (you'll probably have seen that on secure websites, some of which also have content via plain old HTTP), FTP, Gopher, Telnet, SSH, IRC, etc. In other words, it's the HTTP that says "this is a website". That's the important bit. The : is an important part of the URL - it's part of what defines a URL. The : separates the protocol (i.e. http) from the host (i.e. the server name). The // doesn't add much, but it does allow same-protocol-relative hyperlinking, which is useful for web developers because it means that they can type URLs that say "download the Javascript file over HTTPS if this page was loaded over HTTPS, or over HTTP if it was downloaded over HTTP". The www. really IS optional. Some web servers require it to be present; some require it to be absent; and others don't care either way (or will use a redirect to "correct" it for you). There are some folks who get quite militant about it and insist that we really shouldn't have www., and I'm somewhat inclined to agree. Back when the web was young, it was convenient to help make web addresses "look" distinctive, but nowadays they don't really add much.
Active Directory holds for itself the root of its domain. So if you use the same domain for both your corporate Active Directory and a website then you suddenly have a conflict. This mostly isn't an issue because Active Directory is usually only used on internal, non-routable DNS spaces. So in the public DNS space a company can default forward all requests for the root domain over to the corporate website and everything works. Internally, requests for the root domain will route to your nearest Active Directory server. Of course best practice design is to use a different DNS name space for public and private zones, but most companies (especially the small ones!) don't bother. So anytime the root name space is dedicated to any non-www service then some other name is used to route traffic to the website. For years the default alternate name has been www. You could also use the name of the specific web server, but that's harder to remember.
Because all browsers and networking equipment everywhere would need to be re-worked to accomodate that, and it's entirely pointless todoso. You can just type in "hubski.com" and it will direct for you in most browsers, isn't that essentially what you already want? HTTP, like others have said, is extremely important and just part of how the web works. The web server and the client need the info to determine different actions and setup for the connection. For example, HTTP is port 80 unsecure web traffic, that way you and the server both know what to communicate on and how. If it's HTTPS, thats SSL secure traffic and is on port 443, again, important information for both the server and you the client. It's part of the protocols that make the internet work, they need that information, and again you can just type in "hubski.com" and your browser will figure it out for you, so why change it? Because you don't like seeing it once you connect to the site? Simply not a good enough reason to change the architecture of the internet. www really isn't needed for most sites anymore, and even if it is, again, typing in google.com will take you to "http://www.google.com/. So you don't have to type it out, it fills it in for you. Google.com is what the DNS servers keep records of, www is just attached once you connect to google as that is what their servers send back. But it's not needed. Hubski for example doesn't return that. I build websites and work in web infrastructure. Our sites are all HTTPS, but we don't respond with the www. But trust me, the HTTP/S parts are pretty important, and define how the website will function.