Hi, I'm just learning to knit with needles, but I've been using a loom for years. To be honest, the two are similar in some ways, but very different in others. It's true that there are less things you can make on a loom than with needles, but it isn't just limited to hats and scarves, the more people start using looms, the more patterns come out. Bev's country cottage has alot of needle & loom patterns, and for a beginner loom knitting might help you to get the basic concept down, but it's still different from needle knitting.
When it comes down to it (in my humble opinion):
-Loom knitting is easier, but with less options
-Needle knitting is harder, but with more options
Either one would be good to start with, if you have the patience. Maybe try a little of both & see which feels better for you