One major problem with what you've said above: Wikipedia has only one article on a topic, no matter how many synonyms there are for the major word we use to entitle the article.
Synonyms for stupid: brainless, dense, doltish, dopey, dorky, dull, dumb, fatuous, half-witted, mindless, oafish, obtuse, senseless, simple, slow, thick, thickheaded, unintelligent, vacuous, weak-minded, witless. Related terms: feebleminded, retarded, simpleminded; foolish, idiotic, imbecilic, moronic.
These terms can't all have their own articles to contain their etymologies, they would mostly redirect to "Stupidity" on wikipedia if anyone bothered to make redirects for them all. If we determine that the etymologies are notable, where do they go? Clearly none of them would belong in the "Stupidity" article.
If the word it notable, then it can have its own article. "Moron" and "idiot" both have their own articles, for example, despite their current meaning being exactly the same as "stupid".