One of the things I learned at baking school was the in's and outs of bread making. I am in no way an expert, I still learn things, however I will not forget learning about gluten! My chef actually yelled at me one time for being "too mean to the bread". Yeah.
The picture below is what a tear in the gluten looks like- you might have to click on it to get a bigger view.
Tearing will happen in the kneading process. Basically, Gluten is what gives the bread structure, how it will hold shape. It's texture, so it wont be a crumbly mess, and it's strength. Your flour type is what will determine your gluten development potential. Rice, potato, and oat flour don't have enough proteins to develop into gluten. (hence the gluten free bread section )
So when your flour meets liquid, it absorbs and then as you knead, it begins to stretch and pull in to long strands. Like rubber bands if you will. The tighter those rubber bands the better the bread.
Now when you are to rough with your bread during the kneading process, or don't knead properly, you can tear that very gluten you are trying to develop! your goal is a smooth round ball of dough at the end of the kneading. Make sense?
Hopefully it does and hopefully you can now tell others to "Stop tearing your gluten!"