Why is Sayaka and her retarded boyfriend even a part of the story?

The story is about 2 lesbos trying to be together in a homophobic society.
Was the Sayaka side story just a shitty attempt at extending the length?

>>12
The only downsides are that the writing is more straightforward and straightforward than the series average, and the OST is underwhelming. It's a deconstruction of an average magical girl show rather than a deconstruction of a typical mahou shoujo show, so it's more focused on the character interactions between the characters.