I can understand perfectly why people have told you it's wrong.
First of all, the collocation "dependency on" is extremely common and also quite standard. There is also no reason whatsoever not to use it in your sentence.
The next point is that the verb "reduce" really doesn't work well with "away from".
You ought to choose a verb that has more of a sense of movement, such
as "move" or "shift", if you want to add "away from".
In short, the word "dependency" doesn't work with "away from", and the verb "reduce" is also problematic with "away from". That's two reasons right there NOT to use "reduce its dependency away from".
So, what do you think? Do you think the people who have told you it's wrong are right?
