Those who are lucky may think they enjoy it, for a time, until their bodies wear out and everyone they know dies. But even then their enjoyment comes at the expense of the suffering of other beings.

If you start off with the assumption that life is suffering and any enjoyment is a temporary illusion, no amount of evidence suggesting the opposite will convince you otherwise. But simply looking around will reveal much beauty and happiness, plain for all to see amongst the (also existing) gloom and depression.

Not everyone sees life as unending torment.

I think I've seen both sides. I no longer suffer very much, because I largely recognize the ego self as a delusion. However I experienced intense suffering when I was young. While suffering may not be real in an absolute sense it is very real for those who still cling to themselves.

I don't see any way to justify that suffering just so that some can experience joy and happiness, which as far as I can see have no true inherent value.

I'm sure some do, but using your enjoyment of life as justification to have a child who has no choice in the matter and could or could not enjoy life themselves is again, selfish.

All the people who intentionally have children? Based on how much people complain about life, I would doubt that.

Many people are hypocrites in that sense.