please explain to me why so many people are calling Trump treasonous for not tearing into Putin over things that happened on Obama’s watch

Could somebody please explain to me why so many people are calling Trump treasonous for not tearing into Putin over things that happened on Obama’s watch...things they never took Obama to task for when he allowed them to happen in the first place. Crimea, Syria, Ukraine, Airline shoot-downs, Election Interference, all under Obama’s nose. Welcome to the new Bizarro America of the Radical Leftist Democrats.