why doesn't southwest do a European Business Class idea?
 

Knowing how intra european Business Class works, it really is just the same coach seat but with the middle seat blocked, so since Southwest sells Business Select fares, couldn't they jack up some of those prices and include a blocked middle seat for flyers on those fares? The boarding pass could also serve as a reserved seat doc? The FA's could block off a certain amount of rows depending on how many BS fares were sold?

You really need to have assigned seats for this to work. WN has so many direct flights that are not non-stop. So lots of thru passengers. It would be a nightmare to try and police a "blocked" middle seat. Plus many WN flights go out full or near to so they don't need to entice people to fly.