Pilots and university students are two examples of target audience, do you believe these two groups would be distracted and confused by being able to add a PDF to an email reply?
Frankly, yes. People who say this can be done simply and elegantly are ignoring the fact that iOS is designed to be simple to use, applications are sandboxed, and designed to manage their own documents. I imagine there are pilots who would like to have a menu option in replying to an e-mail that would allow them to automatically send their expenses along with the reply. It's not going to happen. Apple consider every addition to the UI very carefully and consider it not just on its merit but how it will affect typical users. As Mr Ive says, they throw away 1000 bad suggestions for every good one. And let third parties provide apps to cater for edge-cases.
So removing this option would completely change the UI?
Of course it would. If new UI functionality is required, e.g. provide Pages with an option to select a document that doesn't involve the option to create documents at the same time, that is by definition a change. Likewise for every other app that creates documents, with the exception of images, which also has separate create (camera) and view (photos) functionality.
Are you saying the average iOS user couldn't handle choosing the correct document in an app like iBooks, DropBox or Pages?
No. I'm saying the average user does not want their out-of-the-box Mail UI compromised by catering for severe edge-cases like the one you imagine, and Apple
certainly don't want to compromise it.
The options menu is hidden away and only visible when you want it, it's not disturbing anyone who doesn't care for it.
But hell, let's play your game. How about adding a setting in Settings -> Mail? An on/off switch for the possibility to add files to an email reply, being off as standard? This would, according to you, not be confusing for anyone, nor would it, according to you, change anything else.
Whilst I personally wouldn't have a problem with that per se, I'm sure Apple would. Even the Settings app is something that is considered on its merits, and additional configuration options require a
very good reason to get approved. That's why there isn't a configuration setting to colour hyperlinks green. Believe me, there are some users who think something like that would be a great idea.
What could you possibly have against this, without being inconsistent?
The option to add an arbitrary attachment is only half the matter. The issue of app and document selection, sandboxing and security remains.
There probably are a few hurdles for the programmers, but you're talking about iOS being abandoned by the majority of users due to them being so confused they wouldn't know what to do and simply put down their iOS devices and never pick them up again, should it be possible to add a PDF from iBooks to an email reply.
I'm saying nothing of the sort. There are undoubtedly very many programming hurdles, as you put it, to overcome, may of which you will be blissfully unaware. And you're doing it again, harping on about your favourite document format, PDF.
If - and it's a very big if - Apple every got round to linking documents from one app to another, other than the very user friendly example of images, there's a lot more to be considered than just catering for PDFs in iBooks.
Do you really not see how ridiculous it is to claim the popularity of iOS devices would stand and fall with not being able to add a document to an email reply?
I make no such claim.
Do yourself a favour. Get an app that does what you want.