As long as you don't shine it in their eyeballs, there's nothing wrong with a laser pointer.
My cats love the thing. In fact, when I go to the counter to pick it up, they know what's coming and start meowing and getting excited.
When I turn off the lights and go to the couch, they all come charging towards me knowing what is about to happen.
They play until they are tired out and never once have they been "harmed" by it.
I, too, will sometimes throw a treat to them at the end of it all but that's not for them to finally "catch" something, it's because I want to give it to them.