I've seen that three times today and plenty of times before that.
So let's try a metaphor to help us examine this argument.
You are homeless until a man gives you a house. You don't ask him for a house, you just find out one day that you have a house. It's an okay house, decently maintained, taxes prepaid, utilities prepaid. That's awesome, right? Sure it is.
So, a month after you move in to your amazing surprise house, a man comes to your door. He tells you that he gave you the house and he'd like to ask you for a favor. Sure, whatever you need, right? He gave you a house, how can you refuse?
He takes you to his property, all 5 acres of it and ask you to mow the lawn. With a push mower. It's 100 degrees and humid. Of course you do it. This guy gave you a house, how can you complain about mowing 5 acres with a push mower in high heat and high humidity?
The next week, he asks you to paint the outside of his 5 story mansion- with a 1" wide brush. Two coats.
This goes on and on until your benefactor is taking up all your time with his requests.
That's kind of accurate, right? I didn't ask to be alive. If I hadn't been made alive, I wouldn't miss it. If I died right now, I wouldn't know the difference. And being alive is difficult at best. So why am I supposed to spend a lifetime thanking anyone for this?
But wait, it's not an entirely accurate analogy, is it? At least not concerning Christianity, or at least Christianity that believes in eternal hell, anyway. Okay, let's rework the analogy.
You're homeless. You get a free house. Some years later, your benefactor appears and tells you that he needs you to do something for him, but he's not going to tell you what. You need to figure that out for yourself by reading certain books he has written. Except a lot of people have written using the same name, so you'll have to figure out which books he actually wrote on your own. These books were originally written in Finnish, and you don't speak Finnish, so you'd better hope the English translations are accurate.
Oh, and he won't tell you how long you have to complete this mystery task, but if you don't do it in time, he has evidence, really believable evidence that you ran a child pornography ring and he'll give it to the police- and the news.
Good luck, now thank me for that house.
That's actually nicer than god, isn't it? I mean, eventually your prison term will be over, or you'll die in prison, but either way it's done. Hell is forever.
Now get down on your knees and thank god for this wonderful gift he's given you.