boil 45 minutes?

I'm brewing using kits from Cooper's, with liquid malt extracts and powdered 'fermentable sugars'. The directions say to boil water, turn off the heat and add the syrup + sugars, then add all this to the fermentor right then.

In one of the beginner's brewing books (author's name stars with P?) he says to always boil for 45 minutes.

This confuses me. Wouldn't that just caramelize the sugars? I can see the point of boiling for long periods of time when you're boiling hops or grain, but why boil syrup and sugar?

Thanks for answering newbie questions!

If you are using a pre-hopped kit, there is no need for a boil. Boiling extract for any length of time is for hop utilization. Are you adding hops to your kit?