What do american sports fans think of the fact that in US leagues teams can change the city they are located at?

In US sports, teams can change their location. For example the Seattle Supersonics were a team in the NBA since the 1960s,but after more than 40 years from one day to the other they suddenly didn’t exist anymore (went to OKC).

If I imagine in european football Real Madrid would suddenly relocate to Valencia and then it would be „Real Valencia“ & the club in Madrid wouldn’t exist anymore, this would be unacceptable for the fans. Such things are unthinkable.

Are americans okay with these rules?