The upgrade requirements are "vigorous", with the average flight time of an upgrade candidate being around 7000 hours (some a lot more, some less). The minimum requirement to upgrade is 4000 total, 1000 B737 and 500 flydubai. There are then several checkpoints to reach the upgrade, including a panel interview with the Chief Pilot and Head of Training. Not really seeing the drop in experience you are mentioning.
That said, I don't disagree that our environment is challenging, and it takes a good crew to make it work!