Given the majority of people in the 1980s had a fairly common name (let’s say top 30-top 50) and now those people are having children and there are still huge clusterings of popularity around the top 30-50 names, it would suggest most people with popular names also select popular names for their children?
All this tells us is that there will always be common / popular names.
It's just that what's popular changes from era to era.
These are the names that soon sound dated.
I'm think names from my Mum's era - Barbara, Janet, Annette, Patricia, Beverley, Marion, Sue, Maureen, Judith, etc.
And then from my era - Karen, Joanne, Angela, Nicola, Clare, Michelle, Jennifer, Sarah.
All of these names would've been 'lovely', and 'so pretty' - but clearly not so lovely that lots of little girls are being called them now.
For what it's worth, I grew up in a middle class community of a small provincial town in a small Antipodean country, where we were (are) as susceptible to naming mores as anywhere.
My peers had a huge variety of names - some I've never heard before, or since. E.g. I had two of the swans from Swan Lake in my class alone!
I think it's a myth that people 'back then' settled on a small pool of popular names.
The 'huge clusterings' of popularity are at a national, or really, international level.
But when you drill down into actual communities, there won't be that many children with those names. What you will see is a hugely diverse range of names - and a few poor souls with one of the really popular, unmemorable names, doomed to sound dated in another generation. 
And I would infinitely remember a Larissa over a Steve.