The only thing guns destroyed were castles and that's only for them to return with vengeance in the 16th century. Seriously, instead of eliminating sieges it's statistical fact that in areas where star forts and other advanced fortifications were made all warfare was nothing but a huge list of sieges.

EDIT: Dude, I have more posts than you and joined earlier than you. I almost exclusively only posted in the NRP section. Me not participating in enough RPs, really? You just had a few bad games and try to generalize it, that's all.