Ash has chosen that path to survive, and it was a choice that was very difficult to make and follow through with, a lot of the time.
There were too many times when she had stopped to consider whether she had to keep going on that path and if it would be better to turn back and choose to take another way.
The problem always returned to what was necessary for her survival and attaining what she wished to achieve.
Too few real options were available to her that she could actually choose from, and those among them had few outcomes that could work out how she wanted or with a good result.
Most of them would still result in a bad end or an outcome that would only put her further away from what she wanted and needed.
If she were able to complete the task and get rewarded, then she would have the justification for everything she had done, besides the parts that were more motivated by revenge.
She could just let it pass by as something necessary and a part of her work for Cerberus.
