You'll find this edict repeated in almost every style manual.

If it weren't, there wouldn't be any need to discuss it in a style manual.

Ignore such people and jettison any style manual that urges you to avoid passives.

Almost all style manuals insist on distinguishing fewer (for items you can count, like blueberry muffins) from less (for mass nouns, like cheese).

All of us want to write better, but most style manuals won't help, being mainly lists of peeves.