I beg to differ. This is a good reason to buy a new case:
https://bucket.bluegartr.com/b65ff19...dbee27706d.jpg
There's nowhere to secure the card. Flopping around loose is a disaster waiting to happen. Even if nothing bad happens, the unsupported weight putting pressure on the PCIe slot could end up ruining the motherboard.
*edit*
In examining the motherboard, it's one that has multiple PCIe x16 slots. You could move the card down to another PCIe slot and avoid using the mangled slots in the case. That would help matters a LOT here.