No doubt, pastors or preachers must be called by God and not by heroic ambition.
However, as for the ones in question, they love to serve, some even think they can kick out pastors, these should tell their secular employers that they shouldn't be paid their salary as well for the same reason.
I equate them to the likes of Uzzah. And there are plenty of such today. These lazy fools believe that once they have "chosen" Christianity, they could use their own understanding and their own goodness to help others.
Shouldn't all pastors and preachers spend equal if not more time and hardship in labor and study, lots of study and research than the rest?