The late 70's and early 80's were a truly pivotal time because the old era of wrestling with the tough guys of Race, Valentine, Bad News etc clashed with the wave of characters starting to be introduced like Hogan, Savage, Flair etc. So guys like the Hammer who didnt have much personality like the new generation coming in got overshadowed quickly.
A big example I like to bring up is the World Heavyweight Championship reign of Ronnie Garvin in 87. Flair was at the absolute top of his game during that time and outclassed him so badly that that title reign is largely forgotten, if not panned whereas 10 years earlier it may not have been.
Depending on age or how much of a wrestling historian you are like @stro is, you may not see the appeal of a lot of older guys unless you go outnof your way to watch the older stuff.
I would argue that Greg Valentine actually had quite a bit of personality in the late 70s/early 80s but man he just turned into a stoic bore once Hulkamania kicked off and he became WWF only. I don't think you can watch his MACW work or matches with Backlund and say he didn't have some character and swag, but ultimately he was about as much of a clone of his father as a second generation guy could possibly be, but with less charisma and that style really fell off nearly completely by the mid 80s. Once charisma became the most important thing in wrestling, at least in the company he was working for, he stood out like a sore thumb for his lack of it.