But what about effects that aren't bad or cheap, but just old? What if they were the best, most realistic effects that were possible with the technology of the time, but just look artificial by today's standards because the ceiling has been raised so much farther now? Is it fair to lump those into the same category as effects that look bad due to lack of talent or effort?
If something is completely convincing, if the creators do 100% of the work for you, then you don't need to suspend disbelief. The full phrase is "willing suspension of disbelief" -- meaning, you know that what you're seeing is unreal, but you choose to pretend and play along. Some things about movies and TV are always going to be artificial -- like the fact that they're taking place on a screen in your living room or in a theater, or the fact that there's a whole orchestra playing music that the characters don't seem to notice, or the fact that they cut from one scene to another in a way that real life manifestly doesn't. If you can choose to suspend your awareness of those dead giveaways of fakery, then you're capable of suspending disbelief about effects that merely suggest a thing rather than perfectly simulating it. Willing suspension of disbelief means being a participant in the fiction -- letting your own imagination pick up the baton the filmmakers hand you and carry it the rest of the way. This is something we all do when reading prose fiction and imagining what it describes, or reading a comic book and imagining the characters moving and speaking. Exercising our own imaginations is a basic part of experiencing fiction. So it can't be that hard to look beyond the surface of an old-school visual effect and visualize the underlying idea it represents.
This!
I'm 35, but I've never had a prejudice against shows because they were before my time. Even cheap looking shows today are fine by me, if the performances are there, the dialogue is there, and the stories are there (in that order). I grew up on Nick at Nite, so the TV shows I remember most from my childhood were not the contemporary sitcoms as much as Dick Van Dyke, Mary Tyler Moore, Get Smart, Bewitched, Green Acres, etc. As a teen, I got into the "New Hollywood" of the auteurs of the 60s and 70s.
Since then, I've gotten into silent movies, film noir, Corman, Hammer, and independent horror of the 70s and 80s.
I mean the irresistible joy of recorded media is that it's forever. Why not enjoy the movies, TV shows, books, and music of the past? Especially since the good stuff tends to survive, it's a lot harder to curate the content of the present day without the perspective of hindsight.