On the main page of petitions.whitehouse.gov, it clearly states the following:
"If a petition meets the signature threshold, it will be reviewed by the Administration and we will issue a response."
Combined, the various secession petitions have garnered over one million individual signatures. They have been "open" for nearly two months and haven't received so much as a nod from the Obama administration.
It is thought that the Obama administration picks and chooses which petitions to respond to and not all petitions that cross the signature threshold. The deafening silence on the issue of succession clearly displays this.