I think it's their way of saying: "we have bad project management"
I would think on a good team you have workers who worry mostly about the thing they've been hired to do, and somewhere in authority over them, overseeing the work is a manager or supervisor or project manager that does a few things:
In a situation where this is absent, or there is weak management, you end up with the workers having to project-manage themselves. This means the people that should be worrying about getting work done are also now worrying about how they can coordinate the work, and make communicate between themselves. That's what I assume they would mean by a "fast-paced environment", a job where you have more worries than they are paying you for, and also likely slightly more job duties than would normally fall on you.