(Sorry if my english is not as good as possible)
I have been on this forum for almost an year (first without an account, then decided that i want to post too). I have watched many mocs created by awesome, skilled people and loved the "presentations" provided by them on youtube.
My pleasure comes mostly from building and understanding the mechanism used by others in their mocs. I really love that some MOCs got instructions available (free or paid).
I recently started buying the instructions, even when i have found the moc instructions on sites like lepin or other "brands", because i wanted to support the MOC creator and pay my respect for their time.
People who really like your work and really wanna support you, are gonna find a way to do it (donations or paying for instructions).
The only noble reward you might get... is that someone is happy with your creation in their living room, based on your instructions :).
And as the others said... you might get some monetary value from the people that are really wanna support you. The rest will copy anyway.
But the "fighting agains the copycats" is never gonna end and is not gonna bring you any joy in killing the "respawnable" monster that is gonna do it all over again...
From what i saw on Aliexpress, mostly all of them give the instructions as "bonus" to a bulk of pieces.