> if I could do the same without the intermediate variable

I'm glad I never had to go through such ridiculous hoops to get a job.

If I had I might have been inclined to say "Yes I could but I wouldn't do it because it would be unmaintainable."

Real application programming isn't about being concise it's about being cost effective. Sometimes conciseness achieves that end often it does not. Having a well named intermediate variable can help document what is happening so that the poor sod who has to fix a bug in or extend your code two years later doesn't have to spend an hour deciphering your code to apply a two minute fix. That poor sod might be the very same person who wrote it.