The first time I actually decided to "farm" S10, I duallogged I think an advy and fixer and spent about an hour making 40m (I kept my CRU for raiding). This isn't 40m that was circulating in the game, this was purely invented in that one hour from nothing. Other people have reported making double that, because I think they get relays and sell CRU. But let's stay conservative for this example. Now let's say there's about 6 ideal spots (I bet there's closer to 12 spots, but they're not always taken) to farm 40m per hour in S10, and players farm it 20 hours out of 24 per day. That's about 4.8 billion credits added per day. If people were really making the claimed 60-80m per hour, then it could be anywhere closer to 6-10 billion credits per day. Now that effort:reward ratio is unlike anything else in the game, on top of the fact that it's adding inflation to the game because even all the cities on RK don't suck that much (since the fees are dozens of millions every 30 days).
The problem is that what is good for individual players minmaxing their gains in S10 isn't actually good for the game. Or for other players. And the "anyone could do it" argument doesn't wash because the more people did it, the worse it was for the game. From reading this FwM, it's actually this factor most of all that appears to have tilted their hand.