I agree to the extent that PTI should loosen up on the stance of not talking to the political parties but talking to the GHQ directly. May be they (the political parties) are corrupt, but GHQ is more corrupt than them, so, PTI, as being a political party and advocating civilian supremacy, should play its part in strengthening the political institution (parliament) and respect it as the prime institution.
The rhetoric of negotiating with the GHQ means that PTI itself consider GHQ as over and above the supreme institution of the parliament.
Political problems require political solutions and that can only be debated with the political realities on the ground. If you want to keep GHQ at bay, then remember the Charter of Democracy, which was signed by all the political parties and is still, in its weakest form, had prevented the Army declaring a martial law since the ouster of Musharraf. PTI should learn from that.