I have been using factory method creation pattern for awhile now. I was just recently told that this:
public static class ScheduleTypeFactory
{
public st
Sure looks like the factory pattern to me. I don't see anything wrong with your implementation.
From Factory method pattern:
The essence of the Factory Pattern is to "Define an interface for creating an object, but let the subclasses decide which class to instantiate. The Factory method lets a class defer instantiation to subclasses."
This is exactly what you are doing.
As a side note: a good rule of thumb is that whenever someone tells you something and is unable or unwilling to provide a rationale for their statement, there is a good chance they are unqualified to make the statement at all.