That is Dr. Phil's belief about the world. And I'll tell you why he's wrong.
Human Cooperation = Survival
In our cooperative culture, the one where every person alive relies on the strengths, talents, gifts and cooperation of everyone else... where people who don't cooperate for the common good are considered to be the most heinous of criminals, the most irredeemable of the sinners, the most selfish and narcissistic of the insane...
Yes, we do have a cooperative culture. We need other people, not just to thrive, but to survive. We need others working on our behalf far away from us, and emotionally we need people working on our behalf right in front of us. We need to know that others value our contribution, we need to make a contribution and we need to value others' contributions. Our basic expectation of life is so cooperative, we can actually ignore the vast majority of our experience in any given day and say 'it's a competitive world' based on the few, rare and still largely cooperative aspects of life that we compete in.
For just a simple illustration: Millions of people on millions of miles of road every day totally take it for granted that all the cars travelling in the other direction will stay in their lane... unless they're drunk, drugged, unconscious or crazy.
The Insanity of Breaking-Away
Where is the benefit, to individuals or humanity, to intentionally break a loving connection with anyone? How is it better to destroy a connected, loving relationship with anyone, if maintaining mutual respect and cooperation is a choice?
How is that good for anyone?
How is it good for parents, to connect with their children and hold their success as a success of their own, to support them, to give to them and to cherish them, and then stop? Why stop?
Who benefits when family relationships are destroyed?
That is a John Taylor Gatto theme: the intentional destruction of family relationships is to create a society where individuals identify with the state (or the platoon) --to accept propaganda as truth, to take orders without thinking about them, to sacrifice the self for the good of this flag's team, to help control the behaviour of others who also need to rely on the attention and love of this group for their acceptance in society.
It is also a Gordon Neufeld theme: the intentional destruction of family relationships in order to control groups of school children --to get the kids themselves to mold the behaviour of their classmates to avoid group punishment, and to adhere to each other in a deep neediness so they become attached to external things (grades, approval of emotionally-distant professionals, class rankings, school colours, pep rallies) and more readily-controlled through fear of losing that approval or connection.
An illustration of the effect on children: a small human was visiting our home, and struggling to get her own way in some minor conflict over what to do or how to do it. For her, the next act was Defcon 2: she said, "I'm not your friend anymore." For my children, for whom friendship was a lovely, unnecessary, extra in their family-attached lives, it was a cause for empathy. One of them leaned over and very gently said, 'do you need to call your mom and go home now?' My kids had never experienced the withdrawal of affection as a control tool, and felt no risk in having this one child dislike them. How different would grade 9 be for most children, if they had that kind of stability?
Children grow into adult afraid of rejection when they have already experienced the destruction of attachments. Adults afraid of rejection make better soldiers for governments, better factory workers for corporations, more obedient citizens and more desperate consumers... it's good for the government and the economy to have only a very small proportion of the populace capable of asking astute questions, thinking about the implications (or the foundations) of the propaganda, or resisting the Buy More, Buy Now imprecations of the corporate machine.
Whenever it sounds like it might be good for society, or people, to be incapable of thinking critically about the actions and propaganda of the government... or the environmental organization... or the military junta... or the commercials during the Oscars ... ask 'who benefits?'
Dr. Phil is wrong: to be a mature, stable adult in the real world today, the very last thing that is necessary is intentionally destroying mutually-respectful, human attachments.