BlackHawkDown... nobody was 'hacking'... well, maybe...
anyway, the Minimi is a support weapon and not an assault rifle and even in the BHD movie it is used as support weapon.
In INF the Minimi is easy to control while NOT running around, even while walking you can fire some threatening bursts into doors, walls and other structures to 'support' your forward movement and your fire team easily. While crouched or prone this thing is really deadly. Maybe you still need some training with it and on how to use it effectively or it simply isn't your type of toy that you will ever get used to. But this has nothing to do with the implementation of the weapon itself. If we would add it unrealisticly, with lower recoil and stuff like that, then everyone would be able to use it in CQB, while running, strafing, sprinting and jumping around easily. That's not how it should be and so it isn't.
The m203 btw is not only a Minimi killer... a skilled player can kill everything with this even while strafing.... but I know enough players that can do headshots with a lot of the rifles while strafing too. And I bet that many can kill a guy lying around with a Minimi somewhere too. It all depends on where you place yourself with a weapon and on how well you are visible while doing so. And this has nothing to do with the Minimi at all.
The ACOGs are used by many and many have enough skill to use them very effectively. Same for standard scopes of course.
People do not use the sniper rifles and the minimi just cause they want to snipe or want to fire hundreds of rounds... they use these weapons cause they like them AND are able to use them effectively.
I don't think that someone would play using a sniper rifle if he is unable to control it. Well, not for too long... as you yourself can proove it.
So, don't generalize the problems you maybe have or maybe see in using these weapons. Many out there managed to develop very high skills on these weapons and I guess they wouldn't use them still if they would not be very effective with'em.
Maybe take a training lesson against someone used to play with a sniper rifle or with a Minimi. I guess you will not be able to beat him/her that easily if he/she is really good with them. (This works for every type of weapon of course, not just sniper rifles and Minimis)