Most people don't choose reincarnation. Reincarnation finds their way to them. Perhaps they did something great in their life. Or maybe truck-sama wasn't looking where it was going. But without fail, those who reincarnate are destined for something great. A new life where everything changes for the better. But... Reincarnation isn't always the greatest thing. Sometimes you just draw the short end of the stick. Di Tou just happens to have drawn the shortest stick. Pulled out of his life randomly. Taken by a crazy old eccentric man not as a disciple, but as a body double?! And a janitor body double no less?! Grasping a system to find... It's a JANITOR SYSTEM!? Truly, how unlucky can one get?
If every time he broke the fifty percent efficiency line, the value of the task would drop, didn't that bode fairly poorly? For one thing, although Di Tou had been able to reliably break through the average line, it still took him quite a bit more effort than a below-average level performance. More importantly, unless the jump to fifty was extremely large, there didn't seem to be a reason for the overall value of the task to drop. If anything, it would make more sense for the multiplier or whatever logic dictated the amount he gained based on his performance bracket to not jump as much.
Of course, to test this theory, Di Tou would have to wait until he was able to break past this barrier again to see what the amount gained was.