The article mentions that using script task is simpler if the required mail functionality is complex.

Example: I need to send to 100 recipients one by one with different messages and subjects. I also need to store in database or create a text file having the datetime and email addresses for all the mails sent.This is small example.You can do number of things using script task.

I do not say it's always simpler..........It depends on functionality you need 🙂