Why can't I create a PreparedStatement that does select * from tab where id in (?, ?, ?, ...)?

The problem is that the RDBMS does not support bind parameters for the elements in the IN clause. This is a limitation of the database, not the driver.

What is JDBC?

JDBC technology is an API that lets you access virtually any tabular data source from the Java programming language. It provides cross-DBMS connectivity to a wide range of SQL databases, and now, with the new JDBC API, it also provides access to other tabular data sources, such as spreadsheets or flat files.