The usual order is "Why is this not [ready yet]?" Inverting it to "Why is not this [rose in bloom]?" might be possible in poetry, but it sounds awkward at best in everyday usage. Note: awkward at best is a euphemism for incorrect. Edit: you didn't ask about it, but for completeness I thought I'd mention that "Why isn't this [all over the internet]?" is perfectly fine; indeed, it's probably the ...
The question is: why did the English adapt the name pineapple from Spanish (which originally meant pinecone in English) while most European countries eventually adapted the name ananas, which came from the Tupi word nanas (also meaning pineapple).