No, they did it because they didn't write it with Sherlock and John as a couple.

And since we are talking about the layout of the flat - never forget the semi-transparent bathroom door in Sherlock's bedroom. An original invention of Arwel Wyn Jones if I am not mistaken. 

Well, such a door could have been used to make the best of the bedroom's natural light in a room with no windows.

Well, obviously not for Johnlock reasons!  I do find the bedroom on another floor a bit odd - I'm so used to Victorian flats which are all on one floor.   But maybe the idea was that it was originally built as one house, and then the rooms were let out? 

Why do you think there has never been an adaptation which shows them as lovers, despite it being a popular concept?   (Maybe there has ... but I remember reading that if they were lovers in S4 it would be the first time - hence "groundbreaking").   Is it because people are in love with the friendship?  I suppose Jenny and Vastra (Doctor Who) are lovers, but they are side characters in another show, rather than main characters in a Sherlock Holmes adaptation).  They have been lovers in print, haven't they, so it's just on screen?

ewige wrote:

Well, such a door could have been used to make the best of the bedroom's natural light in a room with no windows.

I don't know about the UK regulations, but in Norway you can't use a room as a bedroom if it doesn't have a window (and the window needs to be large enough for a person to be able to climb out due to fire hazard). 

Well, no one can check if you use it, but when you sell/rent out a falt, you can't advertise such a room as a bedroom.

Oh, I mean the bathroom has no window and would profit from the bedroom's natural light.

Of course Sherlock's bedroom has a window. Duh.

But Sherlock and John are a "couple."   Even more so by the end of S4.  Things have been left open ended once again but they pointedly included a scene of the boys sharing a moment with Rosie.

PARENTLOCK! 

SusiGo wrote:

Exactly. And I still wonder about this phrase of Mary's: 

I know you two; and if I’m gone, I know what you could become.

What is there they could become and therefore have not been before (that is friends, partners, best friends, family)? 
 

Exactly!  We were told explicitly that John IS FAMILY.  We are shown John and Shelrock's relationship completely mended and them acting as a solid unit.  Then at the end we are shown BOTH of them parenting Rosie.
It is left open as to whether or not John and Sherlock inter into a physical relationship, but by this point that is the only thing missing from the picture.
 

Of course anything could happen, but I don't even think it's hinted at, to be honest.  S4 clears up the whole thing, just as Moftiss said. 

But your points:
I think "family" means like a brother - the other family member who is present.  And Mycroft takes that on board, and in the end is willing to sacrifice himself.  I don't think it means John is Sherlock's potential lover.  For one thing, if they can openly say that John = husband, then why can't they acknowledge those feelings for each other in any other way?

Sherlock has already vowed to be involved in bringing Rosie up and protecting her, and was doing that while Mary was around. 

And what they could become - I think it's meant to mean the heroes of legend.  We've seen all their flaws and weaknesses over the course of the show, and this is where they transition into Holmes and Watson (and obviously not Holmes, Watson and Watson! )

I've been watching the new Doctor Who series, and it reminded me of all the drama at SDCC, when Moftiss were talking about LGBT representation and some people thought they were confirming Johnlock.  It did sound at the time as if they were talking more about Doctor Who, so it's interesting to see that right from the first episode of the new series we're shown an explicitly lesbian main character.  If they wanted to show it, they'd have shown it.  I don't think they're meaning to leave it as ambiguous (although obviously, it's fine to speculate!).
 

tonnaree wrote:

But Sherlock and John are a "couple."   Even more so by the end of S4.  Things have been left open ended once again but they pointedly included a scene of the boys sharing a moment with Rosie.

PARENTLOCK! 

I couldn't agree more! For me, it is clear that the three of them are living together, and the happiness they are emanating is obvious.

And I frankly don't care if others need to interpret that as brotherly love. If you want to see it that way, go ahead and do so. If the thought of John and Rosie just coming to visit makes you happy, that's fine.

For me, it is more and will always be because I see it AND because it makes me happy. No discussion about doors will change that. ;-)