Personally I don't see anything wrong with courting a player publicly. Hell its better than tapping them up behind the clubs back.
But there seems to be some "gentlemen's" agreement to not talk about other clubs players. If you like a player you like a player, and if you would like to have them sign for you, what's wrong with telling the world. Sure it will maybe increase the players price cause it shows your desperation (aka Woody's "we can do things no other club can dream about.")
But I don't see it as classless like some say. I'd be more than fine if Ole were to say, Dybala is a player we like, and hopefully we can get a deal, we respect Juve and honor or understand their wishes if they do not want to sell.