On par, AIDS doesn't improve the human spirit, even though people get impassioned by it. The lust for victory that arises from a battle doesn't mean the war is an indicator of healthy relationships between the warring nations.
The battle over open source is bad not because it separates, but rather because it has created a false dichotomy. The way that the current question is phrased proves this. "Purists" are viewed as ideologues not because of existing conditions, but rather because of the failure of the open source community to understand the fundamental posit that free software is built upon: that non-free software inhibits the pragmatic use of all software. If the current argument did not exist, the success of open source software would not be viewed as a proof of a particular approach to designing software that has proven itself economically sufficient, but rather as a proof of a more fundamental rejection of non-free software.