Marie Osmond feels that it will do a "disservice" to them because it demotivates them from having their own career and make their own money.
While this does occur sometimes, you can put some safeguards to prevent it. You can teach your kids how to value money, and in fact how to manage the fortune themselves so they can make even more.
You can also establish trusts which doesn't release all of the money at once, or not until a certain age. You can even put terms into the trust which will not allow the kids to collect the inheritance if they borrow against the trust at any point.
I feel that, if you have normal kids who are at least semi-responsible, you are doing them a big disservice NOT to leave them all or most of your money, as you might introduce struggles they'll have in life which otherwise wouldn't occur.
For example, say your kid develops a mental or physical disability later in life, after you're dead, and can't work anymore. Imagine them subsisting on a small disability payment while your vast fortune went entirely to charity.
Or say your kid falls victim to a financial pitfall out of their control, such as the 2008 housing market crash, which knocked a lot of people underwater and out of their homes.
You don't want spoiled kids who don't appreciate money or what it took to earn it, but you also don't want them enduring hardships which could have been prevented if you had left them enough money to do better.
Additionally, wouldn't you prefer your children live (and their kids go to school) in a better area, rather than what they can afford with whatever job they can wrangle?
Wouldn't it be better if much of their earned money wasn't going toward interest for car and house payments?
I agree with the fat black chick in the video. I don't know who she is, but she makes sense.
I have thought about this myself because I have a child and he's almost 40 years younger than me. I hope I am around a long time into his adulthood, but I also might not be. I've started early trying to teach him the value of money, why you should get good deals, how to recognize scams, why not to waste money even if you have a lot of it, etc. He's actually got a good understanding of that for his age, such as remarking once that we shouldn't go to the Caesars gift shop because it's "way too expensive". I do all of this because I want him to treat money the same way I do, once I'm gone and he has my money.
I would never dream of leaving it to anyone else, aside from Ben's mom.