A small anecdote about the original RCT: while building your coasters, trees weren't automatically removed if they were in the way, you had to manually click them away. Chris Sawyer, who basicall built this single-handedly said it would be too resource intensive. I wonder if this was true, or if it was based on some architecture decision he made early on that would have been to costly to fix, given that he was the only programmer (it was possible in RCT 2, though).