There are some great explanations of what causes porpoising- it’s helpful to have that baseline before engaging in discussion/speculation. Oversimplifying, the airflow under the car creates a low pressure area. As the speeds increase, the low pressure increases, drawing the car toward the ground. Eventually, the car hits a point where there’s suddenly insufficient airflow underneath to maintain the low pressure, the downforce disappears, and the car springs back up. At the increased height, airflow resumes, and the cycle continues.
Horner mentioned it in his post-race interview- eliminating the bouncing is as simple as raising the car back up. However, this has adverse effects on drag and how the downforce is built.
The early design choices by the Mercedes (typically rake angle, meaning that angle of the car relative to the ground) mean it will be greatly affected by raising the floor, making it completely uncompetitive (not that it’s super competitive now).
So, yeah, Mercedes are painted into a corner. Red Bull are in a better situation, as are Ferrari. I think both sides of this argument can be correct here- there’s a safety issue for cars that are severely impacted by this. Fixing the problem via active suspension systems would also penalize the teams that have made more effective design decisions.
The problem is… If Mercedes have created the safety issue through their design, should they be allowed to fix it through a rule change? I lean toward no- raise the car, eliminate the issue, and be as competitive as possible until it can be fixed next year. That’s what happens to midfield and backmarking teams. Should Mercedes be granted leniency because they’re used to being the best, have been the best, and blew it with the new cars? Seems like a simple answer.