Especially because the simpler form often conveys the same meaning with fewer words. Denser meaning tends to strengthen the prose. Most auxiliaries will only add one word (not all), but those single words add up.
Progressive voice is among the commonest. Useful when you want to distinguish between
She laughed when he came into the room.
andShe was laughing when he came into the room.
and other situations where you want to make it clear that an action was on-going -- and where it wouldn't be clear without it. But I see it again and again when the situation is clear without it.Conditionals are a bit trickier. What I mostly notice is doubling up: including a conditional adverb and a conditional auxiliary. "Possibly they might have come through here." Useful -- occasionally -- to double up the doubt. But usually one can go flying.
Or "could" used to mean "does".
Thod the Barbarian lifted the magical sword and plunged into battle. The blade could cut through armor like through butter.
Well, if it could, why isn't it? And that's one of the lucky ones. I have read passages where it appeared that the character intuited what the new magical object could do, and only later did it become clear that the character was actually doing the things he "could" do.On the other hand, there are writers who use "would be able to". Err -- is that somehow different from "could"?
And "managed". This can hint that there was some difficulty in doing something, very shortly, but also very vaguely. If it's important, perhaps it's worth the details. If not, why suggest it?
He managed to open the door.
Was there actually a problem?The door stuck, but he put his shoulder to it, and it opened.
If not,He opened to the door.
Well, usually. Sometimes you want that shade, but I mistrust it.
And I think I will stop complaining now before I come up with dozens more. 0:)
