Some sensei lecture frequently. (That doesn't make them arrogant, certainly; what they say more than how often they say it is a better consideration for determining that.) Others are very, very terse. It's part of their personality and style. I heard one senior aikidoka quip, when asked what he would ask O-Sensei could he ask one question, that whatever he asked he'd probably get an hour-long rant about fire and water spirits. On the other hand, some very famous aikidoka (Shioda-sensei comes to mind) deliberately kept the philosophy/religion out of aikido.
But like Furuya-sensei remarked once, a good teacher is just a conductor of air over the coals...they don't start the fire. (Damnit! That song! Stuck in head!) It's up to all of us. Scary, huh?