>> specious. (adj.) 1. apparently good or right though lacking real merit; superficially pleasing or plausible: specious arguments.
The clipboard specification you linked is not X11's, but Freedesktop.org's... which was discussed and formalized more or less twenty to thirty years after ICCCM was discussed and formalized. So, yes, you were not being specious: you were plagiarizing someone being specious... :)
As I wrote in another post, when I was introduced to mice in the 1980s, that's what was said to me: "this button selects, this pastes, and this opens a context-sensitive menu". This is the simplest possible way to use a mouse, especially if you copy and paste a lot of text in your workflow.