Ask HN: What are your challenges for using/deploying machine learning?

I'm working on a project to build and deploy machine learning models for non-experts.

What are the hurdles for using machine learning in your organization? Is it

1) that data scientists are expensive 2) don't see a good use case 3) have no idea how to get started 4) can build models fine, but deploying is a pain 5) unable to get buyoff from execs or, 6) you have no problems