A "just say yes" attitude leads to certain disaster then because the time to fix the product never comes. Demanding the time to clean up is equivalent to saying no. Whoever is in charge of development needs to have the power to do that and actually use it (if they don't ever use it, they effectively don't have it).

> A "just say yes" attitude leads to certain disaster

Disaster's a possibility. But if an idea has a 1% chance of success, "just say no" usually assures failure, whereas "just say yes" is a shot at that 1% chance.