I don't think they've been forgotten, just people are busy with a lot of things.

My personal view is that the best way to stop a voting attack like the one that happened prior to Hive is the new voting delay feature. Most of the other suggested changes probably couldn't have stopped it, which is why I came up with the voting delay idea to begin with.

I'm not saying the voting delay defense mechanism is perfect either: it wouldn't stop a truly careful and patient attacker, but I think it will stop future attacks from likely real world scenarios.

But beyond voting attacks, there's other potential arguments for increasing the numbers of witnesses, assuming that witnesses are distinct individuals and not sockpuppets. But there's also arguments against that same idea. Both sides of the argument boil down to more witnesses means harder to get consensus on any action to change the blockchain's functioning. So more witnesses will generally mean more likelihood of status quo (for good or ill). There's also additional costs associated with running more witnesses, but this may well be a lesser concern.