Maybe there are just too many regular CPUs all fighting for a piece of the same pie?

Pools maybe help miners figure out faster whether they are losing money, whereas with solo mining high variance could easily lead to people hanging on a few more days, lucking into maybe even a few blocks one day so hanging on for even more days before lucking into another block which might make them wait longer hoping that was the first block of a lucky burst of blocks and so on.

Intermittent reinforcement is illegal as a pay method in some jurisdictions, and even illegal in the form of slot machines (aka gambling) in some jurisdictions, because it is pretty much the best reinforcement schedule to use when you want to wean the workers out of being paid without having them quit...

So it could very easily be that too many people are running too many ordinary CPUs on this with too many of them thinking that if they hold out a little longer while others quit they will start getting lucky again. Meanwhile how many more thousands of new people are starting up, taking a few days to see for themselves whether maybe their build and/or their CPU might be a little luckier than average, and son on... all the usual stories gamblers tell themselves to convinve themselves to put in another slug and pull the lever once again... maybe just once... well maybe just once more... well heck its got to work this next time... etc

And of course all along more and more people who have some amount of electricity they consider basically "free" (already part of rent, whatever) are probably getting involved, they can keep going "forever"...

(I have servers out on the net I already paid for by the year in advance, got anything better for me to have their CPUs work on 24/7?)

-MarkM-