I totally disagree. If you’re not able to respect the national anthem, and feel it’s fine to boo, whistle or whatever, then it says a lot about you.Italy fans boo’d the Spain National Anthem in their semi n’all.
It’s just part of trying to make some noise and atmosphere, fans trying to play their part in trying to intimidate the opposition.
National Anthems aren’t these sacred things, they’re just a collection of words (or not in Spain’s case) sung to a tune. They’re so unimportant, England doesn’t even feel the need to have a National Anthem.
The national anthem is something most people feel strong and proud about. I don’t understand the urge of irritating and disrespecting others just for the laugh of it..