Why true it maybe better to "explain" why you need such a feature then to ask the Dev's why they did something....
I don't like creation applications that restrict their usage in this way.
They've already given us the workaround: make a bunch of empty realms. I think that's silly, but whatever.
A very distant second reason is that I am often in places without Internet access. Even in a major city it's not everywhere, and everywhere appears to include where I've worked recently (blocked) and where I've gamed recently (no WiFi and bad cell reception.) Most of my usage is at home, so this isn't much of an issue to me.
I mean I can't think of ANY game I played in 5+ years that does not need constant internet access.
I almost never play video games that require constant Internet access. In the last five years I've played...maybe four?*, and only one in the past six months.
A lot of the games I play were purchased online and get patches online (if there are any at this point!), but I can still start a new game if I unplug the computer from the network.
Hell watching TV or Movies requires a internet connection and most peoples phones require internet connection. So who cares if RW connects to the net for 2 seconds to make a unique ID for your Realm?
My smart phone is still a cellular phone if I turn off cellular data and WiFi. We still have a land line phone; where that converts to IP I'm not sure, but it's probably not until the actual office given the local infrastructure. (We live in a weird hole in what they've gotten around to modernizing in our suburb.)
My Mom's side of the family lives on a farm about 15 minutes outside of the nearest town. For a long time they only had dial-up because nothing better was available in their area, and even now I have no cell service there. They have satellite TV and some form of fast Internet.
I know a few people who only watch TV over-the-air, including my Dad's side of the family. They decided that cable or satellite wasn't worth the cost. They miss a few things but between what's there and DVDs they have plenty of things they can watch. IIRC, they have some form of fast Internet but no WiFi. (They only have the one computer.)
We can keep throwing examples back and forth, but again it's more about freedom than anything else. There's other freedom issues at the moment too (you basically can't get data out of Realm Works) and I suspect much of what I'm doing right now is prototyping that will be discarded and redone once we all see how sharing content actually works and if/how data is exported and so on. I've been tempted to just put it aside and come back in a year or whenever everything's up and running, but for now I'm playing and learning like everyone else.
TL;DR: Does it stop me from using Realm Works? No. Does it make me not want to use and recommend it? Yes.
* Let's see: the two Star Wars MMOs, Diablo 3, Kingdom of Loathing (the one I've played recently), and...(looks through what's currently installed) oh, I guess I installed Guild Wars when I built this computer. So technically five. Did I mention my favorite types of video games are adventures (point-and-click/Sierra style) and RPGs**?
** I just finished Paper Mario***. That was a fun one!
*** The Nintendo 64 one.