I became a JW with part of my family in 1972 (I was 13). Here in France the expectations would vary greatly according to congregations and individual JWs. In the first congregation we attended, they were very high in general. My father was quite reluctant, often referring to the "nobody knows the day and hour" saying, and he was regarded as "lacking faith" by others. I remember discussing the issue with an elder who was quite assertive and asking him, "What will you do if it doesn't happen in 1975?" He answered: "I don't even wonder about that. It will happen in 1975." Years later he was still an elder.
The oil crisis in 1974 revived the expectations, even in my own family. Some JWs pointed to a sentence in a WT book about Daniel (Let Your Will Be Done? -- not sure of the title) which had a passing mention of "oil" as one issue of the struggle between the King of the North and the King of the South, and it was viewed as a "prophecy in the prophecy". As some conjonctural shortages occurred my father made huge stocks of basic food (flour, sugar, etc.) -- most of it was eaten by weevils in the next few years.
Strangely enough, in the course of 1975 everybody seemed to forget about those expectations. The "normal" course of events, and the busy "theocratic" schedule made it just too unrealistic I guess. The "date" came and went largely unnoticed. I remember an elder joking a few months later: "6,000 years ago, Adam was in his garden and he just caught sight of a lion's tail" -- an allusion to the supposed delay between Adam's and Eve's creations, which was already a well known "chronological parameter".
I don't remember any acquaintance leaving the WT for this reason in the next few years.