You shouldn't dwell on such things. It's tough being a parent and I'm sure they tried their best. I hope it's just mere coincidence that you happen to post this today, on Father's Day.
Having children is a natural urge that people have. I get this urge. I don't even have to think about it. The feeling comes on its own. It's a very basic instinct. For myself I need to actively suppress this feeling and keep it buried deep.
If you're unhappy with your parents, keep your distance (I don't mean totally cut off relations. If you're staying with them, move out and stay at your own place). But don't hold grudges against them for it. This will only ruin you, not them.