Have you ever noticed that most coaches seem to be defensive oriented? Why do you think that is?
I think there can be several answers but the first one that comes to my mind is because it is easier.
Being a good to great offensive player requires certain skill sets such as shooting, passing, ball handling, etc. that need to be learned and then executed under pressure.
On the other hand, if a player has a fair amount of athleticism, a good work ethic, the proper attitude and a strong mind set he can be a great defensive player even if he is lacking specific defensive skills.
In other words, developing a great offensive player requires more time, knowledge, and effort than it does to develop a great defensive player.
There is nothing wrong with being defensive oriented if that is something you truly believe.
However, if that is your approach only because you think it’s easier or because you are lacking the knowledge and expertise to develop offensive skills as well then you are not serving your players well.