Well less hours and same pay in the form of a raise is perfectly reasonable when you provide a substantial value to the company, though this is obviously not the case with your parent comment.
Another thing is that you only tend to add value to a company after a large amount of time (decade[s]) and even so you may not even be adding value after that amount of time.
You are adding value from the beginning or they wouldn't be paying you - that is what you are there for. Caveat - sometime it takes a little while for a new hire to be brought up to speed on exactly how a company does things, the code base, and so forth, but it is rarely as long as a month.
Another thing is that you only tend to add value to a company after a large amount of time (decade[s]) and even so you may not even be adding value after that amount of time.