Here's some news from the owner.
"rom now on you will need to have made 150 clicks if you want to receive your payment.We also require our users to post their payment proof on the forum in order to get paid next time. We are not that happy to insert this last rule, but we are sad that less then 1/3th of the people post their payment proof on the forum.The last 14 referral packages are available before the price will raise. BuxP v2 will be released next week, if everything goes well."
There are two ways you can see this, the first is that PTC's are trying to find new ways not to pay members or the other way is that PTC's are trying to protect themselves and keep their site sustainable.
Honestly It's a bit of both but it depends on the circumstances in which way you would see it more as.