as a way to move from one route to another...keeping all the romance and that.
Higurashi did it and it still made the whole a mystery.
Answer:
1.) Time constraint during broadcast.
Ads 3-5 min
Openning 1 min +
FIRST half 10 mins +
Ads 3-5 min
Second half 10mins
END 1min
Ads 5min
something like that.
They have to make a way to adapt the timing while airing it live. Changing story, shrinking gags that were in the VN, summarizing the dialog and etc.
2.) Budget - I read it somewhere in the net(probably from Danny Choo since he has a relation to JC staff) that its not cheap to make one anime episode.
I think one anime per episode estimate cost $50,000 USD or $10,000 USD. Not sure about the actual cost but its between those two price.
They said that they made a way to adaptation LB where they fit things and not spoiling the "Secret of the world". Other Anime production company weren't able to make that possible.
This is what I think why they didn't make it possible to make a perfect romance route.