The point of all life is to reproduce. It's one of the qualifications to be considered alive. So yeah, without children, life literally loses its meaning =)
1. The definition of life is fuzzy at best. Most of these definitions operate on populations, not individuals.
2. Population fitness can be optimized by many activities: food gathering, art, research, supporting peers, etc.
3. Meaning is a mental construct. Arguing over the absolute "point" of life is pointless, because the epiphenomena of "value" is a chemical cascade in our brains and can be coupled to almost anything. At best we deal in probabilistic generalizations, like "most people find having children rewarding". It's equally valid for someone to find deeply rewarding value in rebuilding engines, and many do.
More directly: I'm gay. I can't reproduce naturally. If you think that makes me less human, let alone less alive, kindly go fuck yourself.
The point of life is not to reproduce. Life simply is, it has no point. What exactly constitutes life is a vague human concept to begin with. You can choose to make your point in life to reproduce, but that does not make other choices of point in life any less valid or real.
BTW, that's a quite smug attitude, no doubt shared by many people, but I personally do not consider reproduction a worthy goal in life or indeed an accomplishment at all. Raising a child well, yes. Getting your sperm in an egg or getting sperm in your eggs, no. To further elevate the life goal of reproduction to the only worthy life goal for humankind to the point of considering people who do not reproduce to be lifeless borders on the ridiculous (not to mention disrespectful to people who can't have children, or for whom its hard (gay people, for example), or people who simply choose not to have children).
Many people are sterile and cannot have kids. They are still alive by any definition. Many people decide not to have kids but are good Aunts or Uncles or adopted parents. Many decide not to have kids but take care of them, teach them, mentor them. There are even, god help us, productive people who don't have anything specific to do with children. That doesn't mean their existence is meaningless.
On the other hand, a man who spreads his genes by rape may be having lots of kids, but he is not doing a good thing, and is probably not leading a deeply fulfilling life.
The case of adoption and the case of rape say pretty clearly to me that love is more morally fundamental than differential fecundity.
The moral purpose of your life is not given by population genetics in any case. It is an error to conflate purpose in the adaptationist sense with purpose in the sense of your life's fulfillment or your moral values.
Different people are suited to different ways of living, and find different forms of fulfillment; it is part of what makes life varied and interesting.
I personally have never leaned towards having children, I have friends and family with young children and I see the benefit and joy they get, but for me its never been a personal goal or desire. Maybe one day it will be and my viewpoint will change.
I consider the fact that I travel the world and experience amazing things, have tried a startup and am socially active most evenings a pretty good testament to having 'lived' as you would call it.
Some selective parenting may not be a bad idea. Unfortunately, there exists people who contribute to the growing population by reproducing in order to either leave a mark on the world or because it is believed that the purpose of life is to reproduce.
That's the prime example of the naturalist fallacy. The way something is implies nothing about the way things ought to be. That we are around because our ancestors reproduced does not mean we must also reproduce. What naturally happens is not necessarily morally acceptable. Otherwise it would also be morally acceptable for me to kill your children and impregnate your wife, as happens with so many animal species.
I recall explaining this to you before. I will value your comments much lower in the future, since I will always have to watch for you being equally irrational about other subjects.
