From the New Oxford American Dictionary:

gin up
(gin something up, gin up something) US English generate or increase something, especially by dubious or dishonest means: the trade press has ginned up a controversy | critics say the program is just a way for big drug companies to gin up demand for their psychiatric drugs.
origin: Middle English (in the sense ‘a tool or device, a trick’): from Old French engin (see engine).

So it’s not an offensive slur (nor a reference to drunkenness), but it is an accusation of dishonesty that people would reasonably take offense at.