What constitutes a normal URL is clearly not very well defined. People have been used half-assed regexes since always and everywhere and I think they should be able to continue to do that instead of conforming to some unworldly standard.
Discussion
is it the length of the URL, or is it the asterisk that trips it up?
I don't know, I would guess the asterisk.
This position doesn't make any sense. Receiving clients can't control which type of URL the writing client is using. You have to deal with whatever comes in or your user will not have a good experience. Agreeing to use a simpler url scheme doesn't solve anything because it just takes one client to break it.
Exactly, one client can break everything, as is happening right now.
I am not dying on the hill of short simple URLs, but the fact remains that each client must tread carefully in order to be a good Nostr citizen. There is no world in which a decentralized protocol is robust against implementation attacks. It happens everywhere, HTML, RSS, HTTP, Fediverse, Bitcoin, probably many other places.
Thinking of regular web browsers like Firefox or Chrome, there is only a rule about URL formation. Nothing more than this.