Removing a feature that is used, while possibly making chrome more "simple", also forces all the users of that feature to react to it, lest their efforts are lost to incompatibility. There is no way this can not be a political decision, given that either way one side will have to cope with the downsides of whatever is (or isn't) done.
PS: I don't know how much the feature is actually used, but my rationale should apply to any X where X is a feature considered to be pruned.