Channel switching

Sunny Hundal asked

Observer columnists asks readers to follow Archbishop Dr John Sentamu. But fails to link to his twitter page. WTF?

and this got me thinking. I assume that this was in response to Vicky Coren bringing it up, I'm not sure if the plural was a typo or if someone else had mentioned it as well. Now a lot of this is speculation, I don't know the minds of the people involved if I were a real journalist I could go as far as to ask but...
The strongest reason I suspect is that the piece was written for a real ink on paper newspaper, and newsprint currently rarely has the extensions installed to make links clickable and have the request handled by an adjacent web browser. So you have the problem of how to communicate such a link:

• In full? That is quite a lot of typing to get right and there isn't much in the way of error correction if you miss a letter^[1].
• As a shortened URL using tinyURL or similar? This reduces the amount of typing but is even less forgiving of error when glancing between page and keyboard to type it in from the page.

No the easiest thing to do is to let people use search. It took a matter of moments using a popular internet search engine to find what I was after even with a spelling error. I expect that the set of people who actively use twitter but couldn't find Dr Sentamu without the help of a printed link is very small indeed.
This is actually a current trend in getting people to channel shift from offline to online, look at the next billboard poster for a blockbuster movie for example and it is more likely to have a stanza starting "search online for:" and some carefully chosen keywords than one starting "www" (and heaven forfend anyone use the dreaded "http://"). Previously attempts to get you online where more information can be fed to you, and in a marketing context you can interact enough to help them target you, have included 'innovations' such as posters with infra-red transmitters that would send you a link to online information and two dimensional barcodes such as the QR Code neither of which really caught on here.
Now back to naked unjustified assumptions, suppose Sunny wasn't reading a paper copy of the Observer but the online edition, in which a hyperlink has been added to the text which links to the guardian.co.uk aggregation page for the Archbishop. Now it could be reasonable to expect that this story could have had a link to the twitter profile in question, it would have been virtually uncontroversial to add it to the piece, there is no doubt that it would fit. But I suspect that if you had the job of trying to mark up stories in this way on the site as they transitioned from print to online more often than not you would need to consult the author of the piece to confirm that what you were linking to was correct.

^[1]Some ISPs catch requests for non-existant domains and redirect you to a search page in the guise of being helpful but this breaks a number of things that expect when a domain doesn't exist to be told so. Luckily although my home ISP does this it also allows me to opt-out.