What is the motivation for the use of 把 or 将？
it's a simulation of english grammar, after may fourth movement.

就是把戲劇當成一種時髦 is roughly:

that's, (就是) to treat (把) drama (戲劇) as (當成) a (一種) trendy things (時髦)

imo, modern days 白話文 is un-xxxx-able; using western (english?) grammar to write, or analyse written chinese is, well .... i'm not dare to say it openly.

personally, i read &amp; write literary chinese as far as i can.

edited.

那時戲劇界有一種很不好地風氣，就是把戲劇當成一種時髦。


this sentence in literary chinese, it could be (there're ways to express the idea, here's just one of the attempt) written as:

時風澆薄﹒以戲為髦

that, the structure of "把 a 當成 b" is represented as "以ａ為ｂ"; so, the character "把" was seldom used in such situation.

But this use of 把 is not found in old Chinese texts from say 1000 years ago? 


no, 把 was not used in such situation in the past; based on my experience.