Ok, you claim you are plotting 40 per day. With one PC or more?
Secondly, whenever I hear adults talking about 15 year old kids I wonder whether the one who is talking is 12 years old or less! 
P.S. The fact that you are plotting 40 days per day and you earn “more”, still means that you make less every day…simple maths my friend, for six year old kids! 
Hpool is simply accounting for all the fake plots on their server stealing everyone’s coins. They can’t stop this so they are adjusting their estimates down accordingly so that users have better expectations of their losses.
Where is the evidence for these so-called fake plots?!
They put out a statement themselves a while back saying that they where having problems with cheaters. quite a few Chinese sites and chat groups also reporting that it is possible to cheat.
Also, the reported pool size by Hpool is around 20% bigger that what you can see on chain in terms of block rewards. So that pretty much settles it.
The rewards they pay out are XCH won (visible on Chain) / Pool size (according to their numbers)
i’ve just stopped last night with my last withdrawal. thanks to mad max i’ll replot and solo farm in no time with new keys
Via their own admission.