Don’t say the z-word

I always they don't call them "mechs" in-story because it creates the idea that nobody every thought of giant walking/battling human piloted robots before whatever crisis appeared in the story. Alternatively the in-story universe recognizes that fictional mechs exist like Gundam etc, but the new name is used to differentiate between in-story fiction and in-story fact.

"Remember when we were kids and watched mechs Voltron and Gundam on Saturday morning? Now we're Jaeger pilots!"

I'm pretty sure most mecha fiction writers don't use the word "mech" in universe becasue FASA trademarked the term as related to the Battletech franchise and it's still enforced by Topps.
- TIL

How come nobody knows what zombies are but everyone knows what aliens are?

The answer is because aliens have been a topic of speculation for ages. It’s similar to vampires. Vampires have their own lore from books. Zombies don’t have that. They have other zombie movies. The only way for someone in a zombie movie to believe in zombies is if they’ve seen a movie about them or they have previously experienced a zombie outbreak.
It’s entirely plausible that individuals in a movie’s universe might contemplate the possibility of extraterrestrial life before an alien invasion.
It’s equally plausible that people have encountered the lore surrounding vampires before experiencing their first encounter.
It’s highly unlikely that people watched a zombie movie and then experienced a zombie outbreak.
- I mean... Zombies are a Haitian voodoo thing.
*Xeno scum

Shaun of the Dead though...

https://youtu.be/FqNQbdD3kLw?si=Yo1yqZQepOCXmMLq

Shaun of the Dead is a parody of other zombie movies, and it humorously highlights the fact that other zombie movies are hesitant to utter the word “the Z word” without raising questions about its origin.
- yup you're absolutely right!
  I wrote that comment a bit tongue in cheek as opposed to being a contradiction ... when I came back to my comment I realized I'm just too tired today to have conveyed that well enough
SI spotted

What are the mecha shows?

Gundam, Evangelion, Transformers, Macross, Aldnoah Zero, etc etc. There are some more nonjapanese examples but I didn't see much of those myself. I think MegasXLR or something was one? Live action of course I've seen much less of.
Mech Warrior of course bucks the trend. There are several game series I failed to mention beside Mechwarrior as well. Battletech iirc also uses Mech.
- There are several game series I failed to mention beside Mechwarrior as well. Battletech iirc also uses Mech.
  Just some useless factoid: MechWarrior is Battletech. There is the MechWarrior (mostly first-person shooter with some RPG mechanics) series and a Battletech (Turn-based Strategy game with RPG mechanics) video game too of course but both come from the Battletech tabletop.
- Does Power Rangers count as mecha?
- Don't zoids count?

Because at this point zombie movies are so generic they have to have a way to tell them apart.

Last of Us is unique enough of a zombie franchise that they could call them Zombies and still be leagues ahead of anything else in its genre

our zombies are different

Zombies aren't cool anymore, so renaming is an attempt at making them interesting.

Mechs are cool af, but just calling them mechs makes it boring.

Zombies were being renamed at their peak. Look at the walking dead.
- The walking dead is not peak zombie. It might be peak soap opera.
I think it's to show that the characters don't know what zombies are so when they have to learn the same tired tropes that most zombie mythos regurgitates it makes sense to the audience.