What would cause the dust shield to rub on rotors?

[ninefourteener]

The car failed Utah inspections due to a tiny, stupid, insignificant exhaust leak..... I couldn't get the bolts off, so I had to take it to a shop..... turns out, it wasn't just me... both bolts sheared off, and had to be drilled and tapped. Nevertheless... 100% good to go now

On the way home though..... a slight sound that I've noticed since I bought the car became more prominent on the way home. By the time I pulled in my driveway... my car was SCREAMING with scraping metal.

The front dust shield, on the lowest edge, closest to the ground, came in contact with the front rotor.

I bent it back a little, and the car drives great now (and quietly).

But what would cause this? And should I expect it to happen again?