...and not what you're going to hear in the lockerroom.
If I'm the manager of a dept at work and my dept is failing and causing the organization to struggle of course my employees need to step it up but if all I do as the leader of that dept is blame my staff that is poor management and it really reflects on me being a poor manager.
You get out of people and processes what you put into them. My staff will only work to the level that they've been adequately trained and supported to do, also they are subject to the "Peter Principle" so if I haven't done a good job with recruiting, screening/interviewing, and hiring capable and talented enough people, no matter how much training I do, I won't make a "silk purse out of a sow's ear".
Bottom line is, "the speed of the leader determines the rate of the pack". If I'm not a good recruiter/interviewer/hirer and I'm not going to get people good enough to do what I want, then performance will suffer (GIGO - Garbage in, garbage out).
If I'm getting good people hired but I'm not good as a manager at training and supporting them to do the job, not good at evaluating their abilities and not good at holding them accountable or rewarding them then I'll have very inconsistently performing people and inconsistent results. The few superstars I get will always shine, "cream always rises to the top", because they tend to be self-motivating but the rest will be hit and miss.
In none of Nick's comments have I read where he's taken even a partial share of responsibility for failures of his defense. He doesn't have to take all of the blame, but when his comments continue to point at his players and he says it over and over, he's going to lose his lockerroom and damage the trust. Then his job gets even harder. Bronco has figured this out and you frequently hear him assess a failed performance and he'll be honest about mistakes on the field by players but also mistakes by himself and his staff in not preparing as well as they should, etc. I think that's in the very least, fair. What percentage of blame falls on players vs coaches is up for debate, but I think more will always be on the coaches because they evaluate and recruit the talent and then teach/train them and either reward/motivate successes or hold accountable for failure. That's 3/4ths of the pie (player effort/attitude is the other 1/4th).