No this is not just an opinion. This takes less than a day of work for one single developer to change. This is intended mechanics not lazy or otherwise which you are heavily suggesting.

They heavily balance this game for the competitive scene and feel the .50 is important to balance. As such the Samir and the boats have very little angle of attack on its weapons.

Even with this small angle it's an extremely powerful weapon in the right place and right hands. Nothing at all like the m249 from BF2 this thing can destroy radios, light armor and helicopters easily and needs to be balanced because of this.

Also you could be tracking an enemy and sweep over your own crew and vehicle which can already be done on the Samir even with its tiny arc. In BF2 you couldn't hurt your own vehicle like in Squad. But limiting the Samir even more would make it basically useless.