The fact is that those kids did no work whatsoever - not one shred, and they are getting paid for it by society (by the government, really). That makes it pure charity, which I am fine with, but I think limiting the charity to something reasonable like 10 years is more than sufficient and it might encourage artists to create, knowing that their kids will get a nice little 10-year annuity.
I am sorry, I don't understand the 'getting paid by government' part how does this work out?
So, you're basically saying that if person X wrote the lyrics to a song, person Y wrote the music, they both did it under contract to corporation C, who then hired performers P Q and R to perform it, P.1 should receive remuneration for every reproduction of that performance. At the same time, you're saying that if performer S then decides to cover the song, P.1 should not receive remuneration.
What you also loosely implied (but likely didn't mean to) was that at no time should X and Y benefit from "anyone" performing the song. I say this because MJ was often not just the performer, but also the songwriter (both X AND Y) and as such, it seems his children should have the same right to profit should those works (the lyrics and the tune) be reproduced by others.
In reality, X, Y C, P, Q and R can all be unique, the same, or any permutation. However, all of those variables have their own contracts and their own copyright protection, which is distinct for each role, even if they're not distinct in the person performing the function.
This is why the copyright issue is messy, and likely has no right answer.
What I mean, is that 'everyone' involved in making the tangible product should still receive royalties for that particular product. After copyright lapse though, they shouldn't be entitled to receive anything from people who cover the song or any variants of it as long as the new material doesn't contain snippets from the older work.
I guess, to be more clear is that I believe people should get paid for tangible products they create within the scope of original CP law but the intangible elements should be shared.