Why can't I select multiple project invoice proposals and submit them all to workflow

AX 2012 R2 CU7 Project Mgmt & Accounting:

Can someone please explain to me why I can't click on multiple records in the project invoice proposals list and click on the submit button them to submit them to workflow (other than "Microsoft doesn't want you to.").  My client is about to create custom code to perform this action, but it is not clear to me why Microsoft has disallowed this feature.