I added a new user, but I didn't assign to him the "Delphix Admin" flag neither "JS-Only User".
Then I logged in with this user's credential and the system redirected me to the admin home page.
I cannot find the "Jetstream" menu item (in the upper right corner, under username), but if I put the JetStream console URL
http://[hostname]/jetstream/#mgmt into the address bar of my browser I can access to the JetStream Console. But this user can't create a template neither a container. Neither he can be assigned to any container.
So, you're right! A non-admin user can't work with jetstream console and I agree with your question.
Best Regards.
Gianpiero