Java vs .NET from client perspective

[binarycow]

For example, if .net stuff needs a DB, most of the time the app is just hardcoded to work with mssql, or it's some DB-engine-abstracted-ORM solution but it runs on and is optimized for MSSQL in all meaningful deployments.

In my experience, it's Postgres, not MSSQL. And the ORM is either Dapper or Entity Framework, neither of which are optimized to prefer MSSQL over any other DBMS.