I may be the only one here fed up with this, but here goes.
There seems to be a flood of threads of people saying their lens is bad, it's soft/unsharp, it misses focus, etc etc, when the reason is clearly user fault.
I'm not saying bad lenses / copies don't exist, but there have been so many threads where the only person who can fix the problem is you.
unsharp. You shot a photo at 1/15sec at 200mm.
It misses focus. You shot that at 1.4 and used the center focus point and then recomposed.