Your raising of the threshold to 25,000 without increasing the time allotted to gather said signatures is an obvious attempt to make it more difficult for us people to communicate to the White House (WH).
The purpose of this initiative is to hear the American people's concerns. Raising the threshold when the previous threshold already allowed few petitions to receive a response from the WH is counter-productive.
Regardless of your guys' actual intentions, if you want the increasingly cynical American people to believe this initiative is a genuine effort by the WH to hear out the people as opposed to a meaningless political tactic, either lower the signature threshold to 5,000 or increase the time for us to get the signatures by a factor of 5 - the factor the threshold was increased by.