I believe a lot of posters in this thread are reading the title and then posting a reply without context. The Op is NOT asking to have backpeddling disabled completely, they are talking about the fact you move backwards at a reduced speed, preventing you escaping AoE's and thus making lock-on more of a hazard than a help.

The OP suggests that in lock on mode moving away from the enemy causes your character to turn and run away at full speed, instead of backpeddling slowly.