I have also wondered if maybe everyone's lifetime contracts magically drop in payouts as they approach and pass ROI.
Someone should set up a site where Genesis investors can anonymously share their Payout/Hashrate ratio in bulk, and what they are mining. This would quickly identify any inconsistencies. Ideally people would share a wallet Addy so those payouts could be verified but I don't believe this level of trust would be viable unless only done between trusted friends.
If you look just a few posts up you will see i post payout info for Both Hashnest and Genesis Mining.
Currently Hashnest S3 and S4 contracts are underwater and could be going bye bye soon so do not assume that Genesis Mining payouts are the only payouts that are going down because they are not..Far from it..Hashnest are reputable too and they mine just like GM so you can see from my payouts that what is happening with Genesis Mining is because of the fees and the difficulty, just the same as what is happening over at Hashnest.
Ive been posting daily payout info for both companies for months so its easy to look back and see how payouts for both companies go down...as the bitcoin difficulty has increased especially since November.
Please take a look..i update the payout info as much as i can and it can be a useful resource for everyone..
https://bitcointalk.org/index.php?topic=768931.0