1. Companies do not see process improvement as critical innovation.
Many companies totally focus on innovating their products and services whereas the support functions are considered an afterthought. There is a vicious circle here, because back-office functions (treasury, accounting, supply chain, credit control) usually get the blame if something gets screwed up, whereas if things get well, it's the front-office functions (sales, marketing) that get to celebrate. So less and less focus get spent on actually improving back-office as part of improving customer / employee experience, simply because it's not sexy or fun.
2. Current BPM tools do not support autonomous deployment.
Current BPM tools focus on BPMN conformity and compliance, whereas customers of processes see the notations as yet another thing to learn - and to many it's way too abstract. That's why all BPM deployments need consultants to just help the organizations fight their way out of multiple gateways, messages, triggers, compensations and other dangerous swear words. I have yet to see a BPM tool where organizations are able to fully deploy valid, executable processes ON THEIR OWN.