The thing is, not everyone agrees with this so-called general statement. If you want to be inconsistent, then you'll have to come up with something better than we can do it, because we're right.People can go on about consistency all they like and we realise we cannot be consistent. Who knows whether all the sportsmen or artists who are effective support Putin anyway? But what we are doing is making a general statement of disapproval. If people doesn't want to join us in that it's up to them.
I'd guess that most creative types where against American involvement in Vietnam. Whatever popular support the USA had at home quickly evaporated, certainly after the Tet Offensive of 1968....the US was at war with North Vietnam from 1965-1973. Would the US have been totally within "right" to jail all anti-war activists and to require celebrities to denounce Hanoi? Of course not, and you know it.
The few who supported it - even indirectly - where controversial.
I'll give Merle Haggard as an example. His song Okie from Muskogee comes across as lampooning the anti-war movement as hippies who need a shower. Later, Haggard said the song was meant as a parody of the pro-Vietnam side. Whatever the political content, this song has remained one of his biggest hits.
I also remember reading James Brown's autobiography, and he went into detail about how his decision to visit Vietnam to entertain the troops was controversial. He didn't express any views (pro or con) on the war at the time, and said that he just did it for the men who where fighting. Some never forgave him for making what he thought was an apolitical decision.
Performing a song which is apparently pro-war and going to entertain troops are examples of direct action by musicians during war.
Can Gergiev even express his views as part of his job? I doubt it, unless we want to read into his programming of some dead composer's music as supporting Putin. Entertaining the troops is, of course, out of the question.