Just to clarify what xCon does: it's intended for use with legally-purchased App Store apps that refuse to work correctly on jailbroken devices - xCon tricks those apps into thinking that they're running on non-jailbroken devices.
So yes, the gun-jamming hurts legitimate users, but those legitimate users can use xCon to work around it.
Why would I want to support a developer that treats me as a criminal off the bat? I might as well be a criminal and just pirate it at that point... Self fulfilling prophecies at work.
Pirate a $7 app and subvert the DRM using a Jailbreak tweak like xCon.
It seems that this only hurts the legitimate users, as others will still be able to pirate the app.