It's up to you if you choose to use this aid or not, but it exists for a reason. Outside of hardware, there are also applications you can download that will place a crosshair into any game such as HudSight. I fondly remember using painter's tape when playing the original Gears of War because my aim was terrible and I just wanted to have fun.
People have also been manually creating their own crosshairs for years, so unless you also get mad at the existence of dry erase markers, tape and stickers then this is just a reality of shooting titles.
The thing is, a crosshair or any kind of visual assistance is a fantastic accessibility feature, and not every game needs to be viewed with the scrutiny of tournament competitions.
