Board Thread:Questions and Answers/@comment-33064477-20180221075719/@comment-30499831-20180221210746

Trollmonkey2004 wrote: so they were lied to by wu :( But Wu never told them they couldn't

And they probably literally couldn't. At the time they were connected to the weapons. We know the original 4 ninja's powers depend on Lloyd, so it seems their powers work on different logic.