And Now 20 years later those kids are all grown up. Back then there wasn't such a thing as the collectors market, sure there were adul colletors like us, there just wasn't anywhere near as many of us. So the collectors of yeteryear just had to suck it up and deal with what they had.
But in this day and age figging is a completely diferent game, when I was a kid playing with my Secret Wars Dr Doom I never imagines that when I grew up we would have something as awesome as Marvel Legends. Hells when I had the 90s X-men and Marvel Superheros stuff I though that was the absolute Cats ass. I never imagined they would be improved on, I didn't thik they needed improving on.
So to answer your question, yes the action features are generally the differentialting point between Collectors lines and Kiddie lines. A Good rule of thumb is anything mass market is for te Kiddies, but ML and DCSH kind of debunk that rule.
But that's not to say that action feature lines cannor appease collectors as well. The Spider-man line (From Toy Biz, 2000-2006) Was gret at fitting in some great super poseable collector quality figures with action features too.