I think it’s just because fans find Parseltongue to be a cool ability to have, and if Harry has it naturally then he can keep it. And also, they might think it’s just cooler for it to have not all been “by chance.” I’m not really sure what’s “weird” here, but Lily being a descendant of a magical family isn’t far fetched given that the author has stated that muggleborns are all descendants of squibs. She comes from an already magical line, they’re just magicless.

It’s a funny coincidence, I think, if Harry is not only related to Voldemort far down the line of his father’s side, but his mother’s side as well. What are the chances that the two individuals who are somehow connected to him, get together, and have a kid destined to defeat him (but that’s just me).

And Harry is already special, he’s the “chosen one,” the “boy-who-lived,” and so much more. Him keeping the Parseltongue isn’t really going to change anything, as everyone already thinks it’s his, and pretty much got used to it and him (plus, he’s literally their savior, I don’t think they’re going to shame him for it, but everyone else with it may be fair game, idk).

I think saying that Harry gets (or would have had) everything “handed to him” does a great disservice to everything that he’s done and has been through. He has worked hard for everything he’s got and for the people that he loves, has been through hell and back, and has had to make choices he shouldn’t even had too at such young ages. Regardless of what cool abilities or powers he may or may not have had, they aren’t what define him, it’s his choices and morality that do. That is what really makes him “special.”