Even before the "Silent Design" hubs @
tcs mentioned; Shimano freehubs have been quiet, particularly at the 105/XT levels and higher.
In the late 80s, the 6/7/8 transition era, you had a much higher mix of freewheels and cassette freehubs on the showroom floor. Freewheels click; so Shimano freehubs were made to run quietly to demonstrate their upmarket status over the less expensive freewheel equipped models.
I have some 90s XT and RSX hubs that are pretty close to silent, and some 00s WH-500 wheels that tick, faintly, but you have to listen hard to hear it over the background noise once you're on the road
I think the modern trend for loud hubs is akin to louder exhaust systems on performance cars; it may not make much difference, but it lets everyone know that this is the "Sporty" model.