For customers that just want to modernize their infrastructure it is a very simple to start with IaaS. For older server then B-series is extreamly valuable.
As a CSP we can create an offer to the end customer and a economic deal to get the same kind of pricing as in Azure. But we loose money on that.
If we had the possibilty to provision B-series on Azure Stack then we could move customers faster from an traditional hosting environment to a modern cloud platform. This is extra important with the end of life of SQL 2008 and Windows 2008, which works as a catalyst. The easy road is to move the IaaS to Azure Stack.
Right now we see customers instead doing migrations-projects to remove the workloads instead (this means that the workloads are not moved to the cloud at all, they are terminated instead but these projects cost the customers alot of money and an easier way out would probably be to use B-series server and just move them for the time-beeing to Azure Stack).