The idea of "opinionated" software to me seems to have an unfortunate connotation that the user should always adapt their workflow to the one true path favored by the developer. The benign core of that idea is that your project should have a clear sense of purpose, and knowledge of what uses it is and is not suited for—that's praiseworthy.

But the idea of the software being opinionated—and pushing those opinions on the user—sometimes leads developers to ruthlessly strip out any affordances for using it in a way the developer did not intend or anticipate. Developers should be careful to retain at least some degree of humility and not forget that they cannot possibly foresee every practical or interesting use for a product. When you're being "opinionated", you're not just shutting out the users and use cases you're consciously forgoing, you're also shutting out some that are in your blind spots.