Every situation is different. I'm sure there are plenty of people that spend their inheritances responsibly. However, in the 30 plus years that I've working in the trust business, I can tell you there are also plenty of people that would not spend their inheritance responsibly, and a lot of instances where it has caused considerable family discord. And, just because someone is 50 years old, doesn't mean they have the ability to spend wisely.
If you wish to leave $5,000,000 of your hard-earned money to your children, and don't care what they do with it or how it may affect them, then it doesn't matter much, does it? If you do care, then maybe consider a different plan. And for heaven's sake, as the author says, don't put family members in-between other family member's money (that they think is "theirs") and the other family members. Disaster waiting to happen.