Sorry for the late reaction.
There are two issues here:
1) A bug in rateit. When you have a backingfield, it will only look if that field is "disabled". If it is disabled it will set rateit to be "readonly", if it is not disabled it will set rateit to "not readonly", no matter what you define anywhere else.
I hope to fix this on friday.
In the meantime, your workaround would be to set the input field to "disabled"
2) Also,you have a bit of a mess in your code. The "data-rateit-*" attributes should only be on the div.
Your div also has the class name "rateit", so it will be automatically instantiated by rateit. So your JS call is not necessary.
This would be the cleaned up code:
<input type="range" step="1" min="0" max="5" id="cereview-concept_coverage-input-rating" name="cereview[concept_coverage[rating]]" value="" disabled />
<div class="rateit rating" data-rateit-backingfld="#cereview-concept_coverage-input-rating"></div>