As soon as I read this clarification, I turned to my children (two 12-year olds) and asked if they were grateful to me for their existence (since it's out of the question that they're grateful to any supreme being). They both immediately said no. "Really, not at all?" I asked. Reply from my daughter: "Not with our cell phone plan." Frown.
Pressed to explain why she's not grateful to me for her existence, my daughter made the point that she'd been alive all her life. I do see her point. The truth is, most of us take our existence as something that couldn't have been otherwise. In our own eyes, we are "necessary beings."
Even when we confront the reality that we are not necessary at all--and in fact highly improbable-- gratitude doesn't ensue, or even seem logical. Why should I be grateful to my parents for making me exist when they didn't the least bit have me in mind? I may as well be grateful to the Texas State Lottery if one day they decide to award a prize to any Texas resident, chosen at random, and I happen to be the winner.
My next step was to find out if my kids are glad they exist--glad in the fulsome*, ebullient sense. Think Julie Andrews in The Sound of Music. Answer: yes from one. "Other than AT&T, yes" from the other.
So: not grateful for their existence, but still glad. I find their attitude perfectly reasonable. I think I'm owed a little more gratitude for our cellphone service, which I consider more than adequate, but I don't believe they should be thankful to their parents for "making" them.
If some theists are thankful to God for their existence, why don't atheists have to be thankful to their parents for their existence? Well, reproduction and creature-creating are completely dissimilar processes. There's no reason at all why offspring should feel toward their parents what some theists feel (whatever that might be) toward their creators.
* Reply to email:
Fulsome is often used to mean "offensively flattering or insincere." But the word is also used, particularly in the expression fulsome praise, to mean simply "abundant," without any implication of excess or insincerity. This usage is etymologically justified but may invite misunderstandings in contexts in which a deprecatory interpretation could be made. The sentence I offer you my most fulsome apologies may raise an eyebrow, where the use of an adjective like full or abundant would leave no room for doubt as to the sincerity of the speaker's intentions. [American Heritage Dictionary]I think I'm good here, though I admit I wasn't quite sure when I wrote it!