I'm no conspiracy theorist but to me it has been painfully obvious that certainly in the last year at least, they are trying to reduce the number of free credits available for all.
I understand the credits for PC players have always been inconsistent at best but now have virtually been eliminated for all PC players.
The new survey system was better for awhile but not great, but now I have not qualified for a survey in 6 weeks!
I do think they are making a big mistake if they squeeze the mobile players. Realistically how many players can survive on credits won and would be willing to pay 100% out of their pocket even if they could after being given free ride so long.