Do people [not so] secretly hate their children?

Think about it in this way.
Every parents give 20+ years of their lives for kids. It's a LOT of life clock for any human being.
So, it's kind of not surprising to see some sort of frustrations. Also, when kids turn 18,20,25 it's tough for parents to see even their kids to being in most beautiful years of their lives. Especially in todays world, where everything is about money. Even family relationships.
That being said, I feel my parents never actually loved me.

Before going into it, a lot of people have this idea that their children will be the exception to the rule that kids can be major brats. Then they do none of the ground work to ensure this and are annoyed that, yes, parenting is hard work - work that many aren't willing to do. Some don't even have a basic concept of what parenting is: putting the safety, well being and happiness of someone else above your own. And anyone that has to put their own desires and needs below someone else's, is gonna have some resentment. You'll notice that a lot of people who have kids are particularly selfish, so a lot of resentment.

I don't think it's a matter of people hating their kids. It seems more like they're pissed that they're being forced to do more than the bare minimum or whatever they did before isolation. And they're realizing that, because they have only done the bare minimum, they've made their job harder, and there's no way to escape from this.