Why all the added Gums in Gluten-Free foods?

Have you read the labels on most Gluten-Free products? Better yet, how about the GF Recipes in most of the recipe books for the Celiac and Wheat-Free community? What is up with all these Gums in there -- Xanthan, Guar, and so on?

I understand that without Gluten in a recipe, it can be a bit challenging to reproduce the texture associated with the Gluten-containing original, but for the most part that is the limit of it: a challenge. My family has been baking gluten-free recipes for a couple years now, and we have only resorted to added gums once -- when we purchase our first GF baking book that used the stuff like everywhere, whether it added any value or not. And, fact is, most of what we tried to use in in (per the recipes in the books we tried) ended up just plain bad, regardless of added Gums. Fact is, if the recipe isn't any good without the gums, it probably will remain not very appealing even with the gums. Or, so is our experience.

So, we set out to bake all the "tough" recipes like Cakes, cookies, and even a few breads without using any added vegetable gums or thickeners, and through much trial and error, we achieved results that are as good (and in some cases better) than the gluten/wheat-containing counterparts.

So, where does this prevailing opinion about the "need" for adding all these gums to GF products come from? Perhaps it is "needed" in packaged commercial goods that must last indefinitely on the shelf (though, isn't that the job of preservatives and not gums?).