This is getting out of hand, somebody needs to pull ATX out of the stone age. ATX just wasn't designed to accommodate cards this big and heavy and the cooling is also very inefficient. Case, motheboard, and graphics card manufactures need to get on the same page and start making some revisions to ATX and really ultimately start transiting to some completely new thats built around the concept of the GPU being the most power hungry component in a modern gaming PC (or workstation).
As a stop-gap to a ground up new design put some standoffs on the case (on the motherboard panel), through holes on the motherboard, and add on structural supports on the graphics card that can physically mount to the standoffs on the case so the card is physically supported along more of its axis and not just at one point.