In Turkish eyes, the fight is against terrorists, considering civilian buses in Ankara and Besiktas stadium right after a footbal game were targeted multiple times in 2016 killing more than 100 people, after Turkey opened their borders to allow Kurdish Peshmerga to pass into Northern Syria to help the very same Kurdish people and even Kurdish people running away from the war in Syria were let in Turkish side.
In Turkish public opinion intervention is justified and you can't expect footballers to stand against a fight against terrorism, imagine American players not supporting fight against terrorists after 9/11 and saying "I am against wars, stay away from Afghanistan" and multiply that with some blind nationalism you observed during your visit. This is not like Turkey declared war against Greece out of nowhere, can't expect footballers to stand against it.