Oh yes. I’m facing this VM. and the reason is, here it comes by Microsoft :
For any environments deployed on or after Platform Update 12 , there are distinct accounts, a developer account and an admin account. Customers will not have access to virtual machine (VM) admin accounts on development or build environments that are running in Microsoft subscriptions. Thus, the admin account will be hidden unless the environment is running in their Azure subscription. For more information, see Development and build VMs that don’t allow administrator access FAQ.
The difference is off course money. But think twice , by choosing free option you loose time with your developers = salary
Here it comes :