Viewers should decide where do bits go.
I mean, a viewer should be able to choose whether they want their bit to go to the streamer or to the mods. This would give any sort of revenue to mods, who work freely.
Well either Twitch would have to come up with a whole new system to pick who the bits go to within a channel, and then onboard them all for payment processing when they finally get $100 to payout, or they would just be getting bits to give them to someone else. That is a lot of work for mods who come and go from a channel. You could always set up a paypal link for your mods so that people could donate to them directly for the work they do instead.
If you want to give bits to one of the mods, wouldn't you just go to the mod's channel and cheer there?