Uh-oh. I have this. Both parents. Why is this bad?
I think the main problem is it's a trope that has been done so often in fantasy and historical fiction that it's become a cliche. This doesn't mean it's always bad to have a parent or parents die or be dead. One reason it's been so popular is that intrepid orphans tug at our heartstrings and because
not having living or functional parents creates a pretty serious set of obstacles for a kid to overcome. I've got a story in the works centered around two sisters, and even though they are adults in the story, their dad was never in the picture and their mom died when they were fairly young. They wouldn't be in the situation they are in if this weren't the case. If their mom were around and they'd had a more normal childhood, there wouldn't be a story, or at the very least, the story wouldn't be the one I have in mind.
So maybe that's the question to ask oneself. Is it necessary for the parents to die or be dead? Does their death or absence drive the plot, or a central part of the protagonist's arc, that couldn't be done via another means? Or is the parental death just there, even though it would make little difference if the parent were alive? And are there going to be any unusual or unexpected developments that stem from this arc?
I think there's a huge difference between tropes that are common and don't appeal to all readers and story elements that are simply sloppy or so implausible (or offensive in some way) they knock a reader out of disbelief. When reading through hated tropes lists, I think it's important to differentiate between the two, or pretty much everyone will end up being discouraged. I don't think it's possible to write something that isn't on someone's pet peeve list.
Okay, so two fighting tropes stand out to me.
1. Everyone who gets hit on the head is immediately knocked, silently, unconscious. I want the screaming-in-pain guy who just got hit to give up the hero's position.
I agree with this. It's hard to hit someone so that they're out cold for just a few minutes and wake up with nothing worse than a passing headache. I know plenty of people who have had concussions (which are more serious brain injuries than many suppose and require time to recover) who weren't knocked out at all, or were only stunned for a few seconds.
2. Let me preface this by saying that I am not a male chauvinist pig (does the fact that I referenced that term date me?) I have an issue with the trained woman beating the shit out of the trained man, who is often much larger. Like two FBI agents, or cops, or spies. Don't get me wrong. I can certainly believe that a woman who has fighting/martial arts training could defeat a smaller man who hasn't. But I've seen real fights. Actually been in a few myself. Strength, quickness, and toughness always trump technique.
Do they? If this were so, then the largest, strongest soldiers would always survive (or come out on top) in military encounters, and populations that consist of larger, stronger men (on average) would always dominate populations that consist of smaller, less robust men on the battlefield.
If all else is absolutely equal in terms of physical attributes, then it's probably true (assuming one person doesn't get the drop on the other), but how often are all things absolutely equal? If strength and all that
always trumps technique, then why would anyone bother with anything but strength/fitness training with military and law enforcement personnel, and why would martial arts ever have been a thing?
And even if it's absolutely impossible, so are many of the male-centered combat tropes that pop up (like the "natural" who masters swordsmanship in just a few weeks of hard training). Why does "feel good" (and escapist) fun for female readers attract so much stink eye? it's so damned satisfying to read about a woman beating a man at something he assumes he'll be superior at because of his gender.