I would add that it should be, for a public decentralized blockchain, normal that the TOP 100 witnesses can earn enough to keep their activities. One easy way is to add another backup position. It shouldn't cut the TOP20 rewards much (btw I don't understand the need to drastically cut their earning).
The main problem of a voting system is users awareness and apathy. The engagement has increase the last couple of months but we need a better percentage of active users voting.
Good points worth discussing further.