Tesla did the cost analysis and decided the lawsuits from a few deaths were less than the profit to be made by not making safe doors.
I think it’s much worse than that - I think it’s just because they (well, Musk) thought it would be “cool” to have everything automatic and just ignored or pushed aside any safety arguments.
Not defending the decision. I think it’s bad design.
That said, supposedly the reason is that the doorframes do not run along the top of the window, allegedly to reduce the weight of the car. Because of this, the window itself has to form the seal, which could potentially damage the window if the door is mechanically opened. The electronic button lowers the window as it opens the door in order to reduce the risk.
Again, I don’t support this reasoning. I’m just sharing it.