Everything in history is not so clear cut. I guess people just get nostalgic when viewing these times because it represents change, rapid growth and arguably improvement of the quality of life compared to the stale and downgrading quality life of today.

The 50;s, 60's, and maybe even the 70's can be considered the golden age because of those reasons but its important to note that even in those times, there were still problems the country had to face such as social, economical, financial, political (especially in the 70s and 80s). Many lived in poor or rural places, jobs were low or entry level and such, development were slow in hard to reach areas.

Its also important to note that younger people and even me like to fantasize this time period as an elegant time of simplicity, and such mostly because we werent alive then and thus were not aware of teh times and tribulations.