My biggest problem is having kids who can get the ball high enough and far enough. We have no rush. So thats not an issue.
As to the ones that don't go high enough or far enough, does it appear they would've gotten far enough with the same force if they'd been aimed higher? If so, then they're not getting under it, and if you can't improve that enough soccer style, then try it with the toe and try the drop kick (bounced on the end and bounced on the round side). If you have someone who can punt well, you should definitely try him with the bounced-on-the-long-side drop kicking style; it's just like a punt except the ball is rising instead of dropping on the foot.
As to the demoralizing effect, think how it was for the teams in an 8U spring league around Austin that gave
3 points for a no-rush kick, 2 for a pass into the end zone, and 1 for a run across the goal line -- and there was apparently only 1 team that had a kicker.
As long as there's no rush, if you have no rule limiting practice hours, you can always have kickers practice on their own, anywhere they can find an approximation of a goal. If they're place kicking and have nobody to hold for them, they can use a kickoff tee.