One of the biggest reasons I left a company was because the CTO and his toady, both coming from company X, made a unilateral decision to switch to X's proprietary and expensive framework above senior developers' objections because, in his words, if people leave the company, we can always go back to company X to support the application written in X's proprietary framework. Um, yup. Never mind that framework was totally inappropriate for the application, or that the UI looked like a refugee from 2000. Oh, and never mind that the biggest customer had nothing but trouble in another application written in said expensive proprietary framework.

That mindset plus a dash of RTO equaled me out the door.

Edit: spelling