Yeah, this is the most common response I hear from people who wish to birth a child themselves (the second most common is super defensive haha). I wouldn't expect anyone to give a better justification for it - there *is* no purpose to the argument. I just wish that most people who birth children could see that there's no good reason for it, and not judge people who don't want to birth children. I really don't care if people birth their own children instead of adopt - I'm not even remotely preachy about that because I do respect biology and hormones and all that. But the thing is, I have a legit reason I can explain regarding why I want to adopt... and yet it's still often thrown out as inferior, not actually legit. It drives me nuts.
And for llamas, a short PS concerning adoption - if I have a kid, I would prefer it be my genetic material. I'll be up front about that. Somehow it's pretty selfish to buy into the bloodline/genetic material narrative. I agree with that. But understanding it doesn't make me want it any less. I would adopt, certainly, but only if my preference for my own genetics was somehow unworkable. I don't really have a defense for it, and I'm not particularly interested in formulating one because I see no purpose to the argument. It's just a preference.