Um actually makes things a billion times easier. 

1. I dont ever have to move my Xbox One. 

2. I will have 2.5tb instead of just 2.

3. I can easily take all my games to a friends house and install all my games in 3 seconds. Attach USB, done. 

4. I can label what is on an external HDD. I cant label an internal one. 

Changing internal HDD's is really stupid. Unecessary and fiddly. 

well, thats great, except I dont' care about any of those points.  I have one tv with all my game systems connected to it, and I generally get every game system.  As you can imagine, it gets pretty messy.  Adding in some external hard drives adds to the mess.  

I'm not saying this is an issue for everybody, like you said, it isn't a big deal and some people may like having an external drive better.  Personally, I don't.  I'll still get an x1, but I would have liked the option to change out the internal drive, that is all I'm saying.  

Pretty much what del,or says... Plus you can put other things on it

I used 1 tb worth of data this gen. 

I expect to use 20 tb + for the whole of next gen. Will you really keep changing the internal Drive just to use different things? Its been an absolutre pain in the backside this generation. 

Couple that with moving to buy ALL my movies on Xbox Video and I will fill up an internal HDD quick. A library of installed 1080p films with special features and smartglass features are going to be big filoe sizes. 

External HDD's can be plugged in and removed in less than 2 seconds. Have them labeled to store tham in my entertainment draw. I really dont get the messy thing. They can be put away when not in use in less than 5 seconds.

wow, I won't use nearly that much space.  I might use 1, maybe 2 tb the whole gen. and why would I want to keep pulling out and putting away an external drive if I can just have an internal drive in the system all the time?  Honestly I don't know why this is a big deal for you that I would rather have an internal drive.  It is personal preference.  I already have a million cords everywhere in my entertainment center, and I don't want more random cords and hardware laying about down there than I absolutely have to.  

Again what selnor says... My entertainment system is hooked up constantly to at least 4 devices (consoles, cable box, htpc, etc) the heart of the set up is my external HDDs I don't know anyone with an extensive set up without one at least... You are my first encounter... To me and the other it is simplest, easiest, and fastest way to store multiple data source and format and to link them to the right device, unless they are capable to connect to a data server/local cloud/NAS... And even then it's way more complicated expensive and takes more room... Bit internal drives are the worst.. An external HDD takes about the room of 2 DVD boxes and a cable... I hardly see how that can be a big deal when you probably have like me a dozen cable running behind the closet...
then again to each their own, I'll take the small space and cable trade off with the massive advantage it has over internal HDD

I just assumed you would be switching your internal HDD all the time. I guess you dont use many apps, or keep your games installed. Or watch films off HDD etc. My bad.

Internal HDD is impossibly frustrating for me.

nope, hard drive would be just for games really, and I don't buy that many games anymore, so I don't think I would fill up more than 1TB over the course of the gen.  I really only deal with streaming media like netflix, sometimes I'll buy a blu ray if I REALLY like the movie, but I don't have any plans to switch to digital distribution of movies.  

Obviously, I will have to get an external hard drive for the x1 eventually, but like I have been saying, it would have been nice to have an option.  

you guys seem to be focused on downloaded media for some reason, something I don't do or care about at all.  I generally stream any movies or tv shows I watch through netflix or hulu.  I don't need any storage to do that.  

Also, it isn't a big deal to me, you guys seem to be making it a big deal.  All I'm saying is I would have liked an option for an internal upgrade as that would have been my preferance.  

Not sure what it's worth... Here it is for you for less clutter http://www.amazon.com/Shadow-trade-External-Portable-Silver/dp/B005EGXY4Y/ref=sr_1_2?ie=UTF8&qid=1382993495&sr=8-2&keywords=U32+Shadow%E2%84%A2+1TB+External+2.5-in+USB+3.0+Mini+Portable+Hard+Drive