How can you allow users to create products in Craft Commerce I want site members to login and create products in Craft Commerce, so the products they create should only be visible to them on the back-end, e.g,  user (A) should login and view his products in Craft Commerce, user (B) logs in and only see his products.  How can I achieve this in Craft Commerce?
User/User Group permissions don't apply to Product Types in Commerce like they do to Sections in Craft, so I'm not seeing any easy way to pull this off in the Control Panel.

There is a feature request here you might want to comment on if you think this should be the case: https://github.com/craftcms/commerce/issues/174

You could do this from a front-end template/product admin section if you wanted, but not sure if that would be a valid use-case for you.