I agree with the confusion since there is a physical MX100 and then they called their virtual one (which indeed does not provide the same functionality) vMX100. They should have called it something completely different like vMX150 or something different so people won't make the connection between the physical and virtual.
With that being said from the main page:
"Virtual MX is a virtual instance of a Meraki security appliance, dedicated specifically to providing the simple configuration benefits of site-to-site Auto VPN for customers running or migrating IT services to an Amazon Web Services or Microsoft Azure Virtual Private Cloud (VPC)."
I've never deployed the vMX100, but my understanding of the product when it first came out was that it is basically just a one-armed VPN Concentrator based on the description above. It is to only be used for the Auto-VPN functionality for remote sites (which is where you could apply all those policies/L3+L7 rules etc.).
Sorry your having this problem =(