It is a necessary engineering fix. Any new design they introduce will have to go through extensive testing and verification that will take months. The goal here is to be able to assure the authorities and the public of absolute safety as quickly as possible.

You have multiple factories staying still at an enormous cost because of this. You have angry customers that have billions of dollars worth of planes standing still (while they have to pay interest on those billions of dollars). This is not the time to get creative.

If they were starting from scratch they certainly should have done something better and put it through the usual verification channels. But there is no time for this now.