It lost it's legs because of two statements you made(both of which are incorrect):
1. Coaches don't really matter.
2. You can't do much to develop your players.
I agree there's little difference between a 70 and a 73. But run a 50 out there. And, if there's a difference between a 50 and a 70, there's a differnce between a 60 and 70. So coaches actually do matter.
If you don't play/promote your players, you'll kill their development. So, other than playing them, promoting them and providing them with adequate coaching/training, there's not much you can do to develop them.
So, when you make a statement or two that's outstandingly false, the rest of your post gets lost.