My thoughts are that having a basic understanding of ladder logic is easy. But beginners all know that most programs have enormous complexity.
However with that being said most beginners should start with learning ladder logic.
However, beginners should learn ‘WHEN’ a senior programmer would use ST. What are the advantages of using ST. For instance Vlad has wrote;
*An implementation in structured text allows the programmer to create complex routines and flows that may not always be as easily implemented in ladder logic. For example, a FOR loop would take a single line of code to implement in ST while it requires a separate routine in ladder logic. Furthermore, it’s also possible to leverage string manipulation through Excel in order to create easy to copy and paste code for your simple assignments.
Learn more on his post; https://www.solisplc.com/tutorials/introduction-to-structured-text-programming-in-rslogix-and-studio-5000-allen-bradley
There are times and reasons to use ST.
Just my thoughts>