Should I call the owner of the seedphrase careless or stupid?
Yeah, this could be called the Everest of stupidity. The only thing more foolish might be someone who decorates their car with their seed phrase. If you want to keep your seed phrase with you at all times, it should be stored in a way that prevents anyone else from seeing it. BTW, I always carry my seed phrase with me, but it's completely hidden from strangers. If you wanna learn how I did it,
read this.