The industry has seen multi-tenancy by means of virtual-contexts (some called them route-domains) and hardware based instances with dedicated virtual cores. In my view, both these features have their own use-cases. Some customers need management plane isolation with route-domains so that they can extend a VRF across a firewall, in this case FTD or ASA.

Some customer use-cases are SLA-driven which inherently requires hard fencing in order to avoid noisy neighbors with hard-limits on resources.

In my view, Cisco should not be limiting its approach to multi-tenancy picking one over the other. For supporting industry-wide use-cases, it will be suitable to have both rout-domains and hardware based multi-tenancy.