I personally don't support BitcoinXT because I think it will screw bitcoin up but that dosen't mean that BitcoinXT users deserve to get hacked , each one is free to choose whatever he wants to do , it's sad.
I agree, if you do not like XT and or you are against it then just do not use it. No need for attacking those who do make use of it.
These attacks, no matter how justified they think it might be, might end up hurting bitcoin even more due to the perception that could be created by an article like this especially for those who are new to bitcoin.
I'm personally also not a supporter of XT mostly due to how it was brought about but its your choice on whether you want to use it or not. Those doing the attacking should use those resources to make bitcoin better instead of scaring people away.