Anti-Army rhetoric should not be enough to being disqualified as a party. But being anti-Pakistan should be.
There is also a way a certain stance is communicated. People supported Imran Khan when he protested against drone strikes. The Army was definitely complicit in Washington’s war against our own people in FATA.
However, the Afghans and Taliban are not our own people. Taliban Khan had the nerve to not visit victims of terrorism, Hazara people, because he didn’t respond to “blackmail”.
He was perfectly soft on Taliban and Afghans, and wanted them to be naturalized as Pakistani citizens; and wanted to “repatriate” the TTP inside Pakistan. These are anti-Pakistan stances.
He also did not personally acknowledge the Durand Line as the international border between Pakistan and Afghanistan; and did not call for Afghans (including the Taliban insurgency) to accept it as the international border when he was in power. These are all anti-Pakistan stances that have got nothing to do with Army.
It is perfectly fine for wanting peace (not war) against your neighbors Pakistan, as long as they accept your right to exist with territorial integrity. You cannot have peace when the other side doesn’t accept your legitimacy to exist as a state.