And I can give you 4 Marvel movies which had far better reception. (Iron Man, Avengers, Winter Soldier, Guardians) Movies to which the general audience can actually remember the name, rather than just saying 'the one with the whales'. That's among the people who even remember the one with the whales, anymore, which I doubt is very many at this point. In terms of general audience recognition, Marvel kicks Star Trek's ass at this point.
I reject that.
Guardians does not have a single character, dialogue or situation that was iconic--memorable to the average person on the street. At best, one might ask, "isn't the film with a talking raccoon?"--and that's not the result of a firm hold on the culture. On the other hand, so much about Trek has been a natural part of general culture, that
Starship Enterprise, Kirk, Spock,
"Beam Me Up," (or any number of Kirk-isms), to the point where it actively lives outside of the source. What Marvel movie has that effect? "Hulking Out" once had a minor cultural use during the run of the 1977-82
Incredible Hulk TV series, but its barely recognized today.
Now, it's fair to say Marvel is young and might not last (I personally doubt it will fade away anytime soon, but no one can say with any certainty), but Star Trek itself has not truly lasted among the general audience, either. All that most people remember are the iconic snippets like Kirk and Spock, the Enterprise, Live Long and Prosper. And that's a level of lasting recognition that Marvel could easily match: Iron Man, Captain America, the Avengers, even the Guardians etc, are already becoming icons.
Icons? Where? I suspect you are subconsciously gluing Marvel film characters to their
comic counterparts--with the added belief that the comics are iconic. If that's the case, I counter with an uncomfortable truth: there's a large number of the average population who have not or care to read comics, and they have not become part of modern myth like Superman & Batman.
So, in accepting that fact, the characters you refer to live only in their films, the source live in comics, but where is the true cultural hold for the movie versions? Being a hit in theaters does not guarantee icon status at all, otherwise dialogue and characters from
Avatar, Harry Potter or the LOTR
films would have become ingrained in the common cultural landscape, with its characters, dialogue and situations being as familiar as non-fiction history. It did not happen with the aforementioned films (even as LOTR books were read for several generations before the Jackson movies), and i'm not seeing it with the MCU characters.
Too much output with next to no great entries (probably 1 -3 at best) hurts this expanding blur of a franchise.