I think he means it the other way around. You have a Single page application with routing based on #someRoute, then someone tries to share some link with the #targetText=... which will lead to an invalid route. Or am I missunderstanding something?
Hash isn’t used for query parameters.
For example, look at the URLs used by mega.nz, or any encrypted pastebin (they store the decryption key in the hash so it's not sent to the server).
Gmail used, others used it.
https://stackoverflow.com/questions/15238391/hash-params-vs-...
They could just be perfectly written (for their time), just legacy and not updated, is my distinction.
But not for query parameters per se, for app state stored in the query string (and bookmarkable).
https://stackoverflow.com/questions/15238391/hash-params-vs-...
https://store.steampowered.com/tags/en/Adventure/#p=3&tab=To...