What's the point of him leaving in a friendship path? lol
I don't know what the story will be, but it was said that also on that path things will end badly for either Eric or Max.
The point ... having only one story to write and develop.
Having two storylines - one with Eric and one without - has been a lot of trouble and hardly worth it, since most people don't want him around in the first place. And you can even do a bargain with him, so he won't go after all the girls, causing even more variations.
That means that there's a lot of work for an aspect of the game that only a minority of the players is interested in to begin with.
Having different paths is hard enough in visual novels, in a game like this one it's development hell, espescially for a small development team (after all it's still basically a one man project, even if some of the guys here help with testing and translations).