Since when

That's a weird thing to complain about

 

Both can be, tv shows are more commonly thought of as a series

 

A TV show "series" is something like
"24"
"MARVEL'S LUKE CAGE"
ETC

A movie isn't a series until it's split in parts to make mini episodes something like they done with the movie Blade.

 

Depends are you talking about the movies or the series? There is a difference....in fact the only series I know of transformers is an Animated series.

 

There's many definitions for the word serie. Literally, yes some movies are series but we create words and concepts and associate them together to help us communicate.
It's just that movies aren't always series of movies. And if the movie is part of a serie, you will never have to watch the rest of the serie to understand it.

 

idk I say 'TV-series' but usually shows have more seasons and epdisodes so maybe that's why people call them series.
why does it matter though?

 

Harry Potter is a series of films as it’s following the books

 

since ever