Players sure kept their heads down when Wenger getting booed / jeered / told to **** off every week. Its a wonder why they never spoke up if so offensive.
Its the atmosphere round the club generally... not a happy or content place. Personally no problem with that as we are playing poor, manager precarious now & slipping down the league. Its not a holiday camp.
The manager has been booed, the owner always gets booed & players get booed when out of favour or poor.
I don't think it's the players' place to respond to criticism of another. People have to be allowed to respond in their own way.
What the players could and did do, was express their support for their manager.