Why can't I use spot lights for children's bedroom?

Difficult to say, but could well be that the surface of the spotlight is very hot when on and there is a risk of severe skin burns if touched by a child. Take a look at the link below as this may have some more info; http://www.esc.org.uk/public/guides-and-advice/

I would try a different shop as it's not some thing I have ever heard of. You would not want for instance a baby or child to have a bright shining light into its face or for anyone to come into contact with the heat of the bulb as you could get a burn. The best safest method is LED's as they give off much less energy consumption and therefore less heat and are less prone to fire risks and can be dimmed. Make sure the products are CE marked for safety. Good luck shopping

Maybe they do some kind of magic tricks lol. Maybe if your children can reach the ceiling and the actual bulb itself as they get really really hot.

There's no reason you can't, as long as the child cannot touch the bulbs as they get very hot.

Cant think of any electrical reason as all lights should be safe to use in any house location other than wet rooms. It may be an eye and safety issue in that spotlights are bright concentrated light sources that could damage a childs vision if stared at for any length of time.

The only reason I can foresee is that the spot lights become incredibly HOT and children being children things can happen. I would still use the light fitting but obtain LED blubs as they will not get hot. Hope that helps