You shouldn't have a user account on prod machines. Typically, there's just the user the service runs as. If it's in the cloud, the "machines" are containers. If your company sells on-prem stuff, there's a good chance it's an appliance that's owned by someone else.
If you operate your own data centers, then you need to do configuration management of the machines, so their configurations are immutable/reproducible.
(These problems all arise once you have a large fleet and a large ops team.)
If your fleet is large enough that user accounts are no longer feasible then you probably shouldn't be managing these servers by hand anyway, so the preference of shell becomes irrelevant.
If you operate your own data centers, then you need to do configuration management of the machines, so their configurations are immutable/reproducible.
(These problems all arise once you have a large fleet and a large ops team.)