I personally did use lock-on, and could see where, with the correct settings it became a near aimbot. 90% of the reason I enjoyed using it thought was for the display of how much health the enemy had, this was a giant bonus, and helped me. The other 10% was I had a slightly bad internet connection, and so people would spaz around me and it helped to aim slightly call me a noob, but I didn't use it as an aimbot.
Don't feel bad. A large majority of the people who play the whole game use lock-on. I'm pretty much the only one that I know of on this board that doesn't use it. I'm the crazy one, not you.
"There are two things that are infinite; The Universe and the stupidity of human beings. I'm not sure about the first." -Albert Einstein