That must go back to the days of the WWI (World Wide Inkwell). That bubble burst later in the 1800's when BIC came out with the WWBP (World Wide Ballpoint Pen.) Infographics are great as long as someone actually proofreads them...
I think you're right. So, "ink" is mistaken for "backlink". Interesting. In the age when we have Curiosity on Mars and invent gadgets that humanity couldn't fathom having just 10 years ago, we still can't figure out the difference between an ink and a backlink? Paaaathetic.