On the other hand, there was at least the germ of a good idea there. If I recall, every hero and villain was snatched off the Earth and plopped down on this planet to fight each other. Whether they stayed there for the run of the series or popped back and forth to Earth at the Beyonder's whim I don't remember, but I think the idea of a Marvel Earth with no super-powered beings is fascinating. Consider: there's almost never any natural disasters on Marvel Earth and after the 60s or so not many many memorable crimes committed by rank-and-file crooks. All of Marvel Earth's troubles are caused by superheroes fighting supervillains, superheroes fighting superheroes and supervillains fighting supervillains. If suddenly they were all to disappear -- all of them -- I think the people of Marvel Earth would be delighted and relieved. It would have been interesting if at the end of Secret Wars they all came back and the people of the Earth let out a collective "Noooooooooooo!"
Considering the nuanced relationship between Marvel heroes and public opinion, this is not an unlikely possibility. Remember, this is a world where there are protestors outside of Avengers Mansion because they have no black members and let mutants on the team!
Even guys like Thor and Captain America aren't exactly universally beloved - when Hercules defeated Thor, for instance, when Seidring the Merciless stole Thor's powers, the press was the first to start the laugh parade at poor Thor's expense. Overall, being a hero is much harder in the Marvel Universe.
Something very much like what you describe did in fact happen in the Marvel Universe during Kurt Busiek's run on AVENGERS: when the Avengers returned, they were interpreted as being fakes and viewed with titanic suspicion.
DC fans, on the other hand, viewed "Secret Wars" as Marvel's hastily slapped-together effort to steal DC's thunder with a "major event" of their own, only with a then relatively unknown artist (compared to superstar Perez) and with nowhere near the promise of sweeping change and cosmic import that "Crisis" had.
I wouldn't say that's an entirely fair assessment.
For one thing, SECRET WARS did introduce several very interesting concepts to the Marvel universe:
The second Spider-Woman, who had a great costume and fantastic powers: Psi-Webs, no less!
The introduction of great old bruiser Titania, who has recently been used to extraordinary effect by Dan Slott in his recent SHE-HULK series (which is absolutely worth picking up), where she was made misanthropic, thwarted, frustrated and all around interesting to read about; the story where she obtained the Infinity Gem of Power from the Champion was the extraordinary climax to the series.