It is a coaching culture issue. There are voluntary elements of an overall practice schedule that are negotiated league wide by the players union to avoid things like excessive two a day or padded practices. This is not one of them. This speaks to a lack of attention to detail and a man who knows he should have never been the head coach telling players I will let you decide on if you want to warm up and how. It opens the door to undisciplined behavior and freedom to trusted veterans who in theory know better than the sports science team the franchise hires. It's stupid.
In my professional career I have worked at places that lacked leadership. The telltale sign is to cater to exceptions for individuals rather than follow a system and solve the system rather than the individual. Bad leaders never see how a system causes problems and instead over focuses on the individual as the problem. It leads to suboptimal results.