Yes absolutely. I don't say "no functional constructs" nor does anyone else here that I know of. However, composite LINQ statements, especially involving aggregation can and do become confusing. Obviously it's a judgment call but in many cases, breaking out a complex expression into incremental, imperative steps can and does make it clearer.

The "rule" I apply is "code should be written primarily for people to read and only incidentally for machines to execute" which, although very subjective, provides a good foundation for everyone to start from.