That makes sense. But I think ivy-ffap-url-functions is unrelated; setting it to nil does not change the behavior above. I investigated, and it actually happens because of the following clause in counsel-find-file:
(ffap-guesser) returns /https:/google.com, and expand-file-name on that gives /scp:https:/google.com, so Emacs invokes scp and tries/fails to open a connection.
On re-checking my example above, I found that the same happens for M-x ffap, but I didn't notice originally since it doesn't happen until you actually press RET to find the file, rather than immediately as in counsel-find-file.