Well it was them who coded it, so it's their mess they have to clean up. It might be easier to rewrite some sections of code than optimize the existent one. It's up to them to decide that, we don't have the source code nor are we getting paid to get the work done.

Personally, I think they might consider doing something about it after they get the game to the point it's worth paying for. Optimization will help more people to play the game, especially those with slower systems, but it's going to take a while to implement the fixes
I understand it was them or their interns who coded it, I was wondering out loud in that post how badly it is coded is all.