Green’s Dictionary of Slang

(Aus./N.Z.) a general excl. of dismay, exasperation or disgust.

1940		Mail (Adelaide) 22 June 23/1: Favourite expression with the troops is, of course, ‘Wouldn’t it?’ — short for ‘Wouldn’t it make you sick’?
1941		A. Gurney Bluey & Curley 21 Nov. [synd. cartoon] — Cripes, wouldn’ it? — Wouldn’t it what? — I dunno!! — Dunno what? — I dunno!! — Wouldn’t it?
1941		Argus (Melbourne) 15 Nov. (Supplement) 1/3: ‘Wouldn’t it—!’ Never given the final words (the completed sentence has several variations on ‘Wouldn’t it rock you!’ or ‘Wouldn’t it rip you!’.
c.1943		S .J. Baker Aus. Vulgarisms [t/s] 15: wouldn’t it root you!: Wouldn’t it make you sick! A cant phrase usually abbreviated to wouldn’t it! and popularised by the New Diggers.
1945		J. Henderson Gunner Inglorious (1974) 129: Strewth! Wouldn’t it rotate you?
1951		Cusack & James Come in Spinner (1960) 333: ‘Starve the crows!’ Blue moaned as a plump figure came rapidly round the corner to them. ‘Wouldn’t it?’.
1963		(con. 1944) L. Glassop Rats in New Guinea 181: You woulden read about it in the War Cry. Woulden it rotate ya?
1965		J. O’Grady Aussie Eng. (1966) 88: An exclamation of astonishment or dismay [...] Originally ‘Wouldn’t it root you?’, or ‘Wouldn’t it King Farouk you?’.
1988		McGill Dict. of Kiwi Sl. 125/1: wouldn’t it! exclamation of disgust or exasperation; eg ‘Wouldn’t it make you spit tacks!’ c. 1925.
1988		McGill Dict. of Kiwi Sl. 125/1: wouldn’t it rip your ration book/rock you/ root you/rotate you/rot your socks/make you spit?/make you spit chips?
1999		G. Seal Lingo 66: There are [...] many World War II diggerisms relating to discontent. Probably the most famous is wouldn’t it root ya! ejected as an expression of disgust with pretty well any aspect of the war. It came in various euphemistic versions, including wouldn’t it rotate yer?! wouldn’t it rip yer?! and wouldn’t it rock yer?! even politely as wouldn’t it rot your socks?
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].