The chair you have may very well be a much better chair than the BYU rentals... To sit on, which is why it worse for those around you.

Notice how the picture you posted of BYU's lesser chair ends right at the edge of the seat, so it isn't encroaching on the knees of the person behind?

Now look at all the images on Amazon of the chair you have. Notice how it extends back at least an inch beyond the back edge of the bleacher and has a backwards lean?

More comfort for you = discomfort for the person behind you.