Does the whole team normally sing? If so, then this isn’t stupid.
What entire team sings the national anthem that isn’t from a fascist state?
Outrage over something stupid.
No, the whole team doesn't normally sing.
Watch any NFL, NBA, or MLB game. Do most of the players sing? No.
If you are in the stands at any professional sporting event, look around. Do most of the fans sing? No.
I don't know how it is in other countries, but Americans have largely lost the custom of singing the national anthem at public events. Most of us still stand, and many of us still place our hands over our hearts (though many don't), but most of us -- players and fans alike -- listen while a band plays. If we're lucky. Or we stand and wince while some showboating idiot singer turns the national anthem into some freakshow piece, which is what we should really ban.
At the Netherlands game, Lindsey Horan and Julie Ertz were singing while Trinity Rodman and Alex Morgan were at least whispering along, which is more than most U.S. fans do. The rest were standing impassively, like most athletes and fans at most sporting events. That's four out of the eleven starters. Compare that to the starting lineups at any NBA, NFL or MLB game.