It was discussed at length. My 'vote' was technically for a 10% reduction in witness pay too (as well as SP inflation). The main reason against it though (that I do agree with) is that it affects backup witness pay too, and a lot of the backup witnesses are already running at a loss.

One of the nice things about the SPS, is that once we have a funding source in place, it is then possible for the community to fund changes. If someone wants to make a proposal to the SPS to fund development + testing for a change that increases backup witness pay, decreases top witness pay, and adds more funding to the SPS - that is fair game.

If the system works as expected / hoped, then we basically have a framework for these types of improvements.