It happens. A shame that it did, but Jinako isn't a total bust. She has some decent skills to act as a team support, and is also capable of being a tanky solo servant. There are worse gen pool servants to have spook you.

As long as she's a 5 is all good.

Better her than:

Look at her face: she's laughing at you calling you a clown for playing this ******* game. With time she'll also haunt you in your dreams. Whenever door you'll open she'll be there pointing at you as you failed another banner and smile with delight on her face. WELCOME TO MY WORLD

It already happened to me, in the 7th Anniversary Summon, because I thought I just received Arcueid, it was Ganesha after all, you can imagine that someone wanted to troll me.