I think that's true: Stan Lee's sopa opera sub-plots had a lot to do with Marvel's success. But I think that was only one (very important) element amongst others. I think it was a combination of Stan's soap opera and 50s-MAD-style humour and ironic distance plus Kirby's science fiction/myth/folklore with superhero action into an unforeseeably (not a word, apparently) potent stew that totally revitalised superhero comics - as far as I can tell: my view is of course limited by when I was born and the things I've read.

So yes, I think there's no question, soap opera has been a key element from the beginning and I would say has to be there to help prevent superhero stories from devolving into personally vicarious or worse, politically fascistic power-fantasy. However, it (soap-opera) can itself be over-emphasised, and maybe that's what adamwarlock was trying to say - instead of just blasting us with his soul-gem! 

As always, it depends on the individual reader's taste: I enjoy the soap opera and the power-fantasy and the irreverent humour but in different proportions at different times and with different characters or story-lines.

For example, I think "arrogant" characters like Dr. Doom or Namor the Sub-Mariner or "pompous" ones like Captain America or Superman or Doctor Strange have to be played (i.e. written) "straight". Not that you can't have the bubble punctured from time to time by the right counter-foil, as Hawkeye used to do with CA, for example - though you have to be careful there too: if you do it too often both characters lose their effectiveness. But anyway, to cut this short, certain characters won't work if they're written as comical figures.

I think the same thing is true with the soap opera: what works with Peter Parker or Matt Murdock doesn't necessarily work with, I dunno, the Silver Surfer or Adam Warlock. I think it's a big mistake to habitually treat these larger-than-life characters as if their life-experiences were just like our everyday ones. I said habitually: it can be done occasionally as a bit of comic relief, but if it becomes the norm you've lost that character, you've lost one bit of uniqueness (actually a word, apparently), you've made everything a little bit more the same.