For every great offense, there is a way to defend it. For every great defense, there is a way to attack it.
So it isn't the talent on the team, it isn't the coaching........it is the right talent with the right coaching.
If as a DC you can't adapt to what the offense is doing, then the book will be written on how to beat you.
If you as a DC don't have the talent to do these things, then the book will be written on how to beat you.
So the way to win consistently on defense, is to be able to adjust to the team you are playing. You better be able to stop the run, stop the quick passing, and then get pressure.
Pressure keeps the developmental plays from happening, and causes offenses to make mistakes. It is not as important as stopping the run though, because an OC will control the ball and when your offense can be on the field, if it can run the ball and control the line of scrimmage.
Tape kills when you have pride that your way works, and you are not flexible. (An OC will scheme a way to beat your D)
Tape kills when you don't have the talent to defend what you know they are going to do to you. (An OC will figure out who they can beat on your D)
I have many less issues with the talent than most fans here because I don't think the coaching is getting the most out of the talent it has. I think they are asking talented men to do things that they aren't that talented at. IE... you don't ask a zone corner to play lockdown man all the time. You don't ask a safety that is great in the box to cover some of the elite TE's. You don't ask a zone safety with average speed to be a center fielder or to play man on their fastest guy because he moved to the slot. You have to have the correct talent for that type defense, and you have to be flexible and be able to run multiple defenses with little personnel change. Hard job.
I am not sure exactly what DC is out there that could be flexible, evaluate talent, could teach, excellent with film, and knows to impart their "will"...........but I am fairly certain it will come from either a retired player, or the college ranks.