Absolutely yes, 100%.
Main reason being, everybody has been a child, and thus has a unique perspective on how to deal with children. Doesn't make them an expert by any means, but it's one of the few things I think everybody can have a valid opinion on. I know some very wise people who haven't had kids.
Does it mean it's going to be 'good' advice? Or the right solution for the specific child in question? Of course not, but when it comes to what you consider 'common sense disciplines', everybody's advice is worth considering. To think otherwise is to just limit your available pool of knowledge.
Long ago, I freely gave (mostly unasked for) advice to my girlfriend who had a child, even though I hadn't had any. The conditions I grew up under made me contemplate the parent-child relationship, things like trust. I had friends who had never been 'punished' in the ways I had. Most were malcontent and spoiled, but one of them was very wise and well behaved. I learned a lot from his parents, simply by observing how they treated him. I also had cousins, which I was responsible for, and took that responsibility seriously.
Basically, I had more experience interacting with children than she did. However, she felt since I didn't have kids my advice wasn't really worth considering. Pair that with her degree in Early Childhood Education, and I was lucky to get her to even listen to me when it came to her daughter!
I understood having a kid didn't come with an infusion of knowledge. Ooh, that'd be cool though, like a Matrix kind of upload.... "I know parenting"... But like OP says, there are terrible parents out there. Kids who had little experiencing handling children, and just ended up pregnant. It comes down to relevant experience, which while being a parent can give, isn't the only source of it.
Maybe it was the arrogance of youth, but I met adults who just seemed so foolish to me. I vowed to never do things I hated as a child, like answer "why?" with "because I said so!". (I'm proud to say that I encourage my children to ask me "why" when they don't understand something, and I take the time to explain to them. Alright, this is getting away from the question...
Years later, we had a child of our own. I've changed my mind on some of the things I gave advice on. For example, I was firmly against the habit of letting her child sleep in bed with us. I explained that she'd become dependent on our bed to fall asleep in, or just have a harder time sleeping in her own bed when it came time. Tear the bandaid off in one go, right?
Now, with our own child, I've noticed that I've been faaaar more lenient with letting him sleep in our bed. Was I wrong before? .... Yes, but not because my point was wrong, it was just coming from a different place. It's a valid point, and it has been harder to get him to sleep comfortably in his own bed, because I let him sleep in our bed more.
So I was right in that sense, but I was wrong because I didn't account for the... unselfish compassion that I wasn't even aware existed until I had a child.
That said, there are things my opinion hasn't changed on.