Guardians of the Galaxy is the next installment of the Marvel Cinematic Universe arriving in cinemas August 1st. Some people thought that this film was a bit random and completely unrelated to the existing MCU but i'm gonna tell you why it needed to happen.
Reason 1: Expanding the Universe
With [Guardians of the Galaxy](movie:424073) being placed in outer space (obviously) it has the potential to set up a HUGE portion of the existing comic universe. In the comic books there are plenty of teams and characters that come from other planets or galaxies like The Watcher and the recently brought back Silver Surfer and the MCU so far has only managed to get in to this section a fraction with the Thor franchise. But Guardians opens it up as a gateway, possibly leading to a whole mass of characters getting the film treatment, I mean who doesn't want to see a Nova or Inhumans film? The space element is around a third of all of Marvel. You have one third set on Earth with its characters, one third set in space and one third from the mystical side of Marvel which will hopefully be explored in [Doctor Strange](movie:559685).
Reason 2: Giving it Scale
With characters just set on Earth with just Earth problems its hard to understand the scale of whats happening but with Guardians opening up the universe we can see how important the Avengers are. The Infinity Gems (or stones or whatever) are being set up in the MCU now with Thanos trying to get them we saw the Avengers defending the Tesseract and we may not know how that affects the universe but Guardians shows us that not only is Thanos threatening Earth but the whole universe and the Avengers are one of the few that stood up to him. Guardians basically builds up the scale of how important Earth and the Avengers are to the entire cosmos.
Reason 3: Insane? You Have No Idea!
Guardians serves as an important risk for Marvel partially because it is exploring some of the whacky stuff from the comics, so far the MCU has been fairly grounded, fairly believable (with the exception of Thor) but Guardians shows coo-coo on a whole new level. Before we had some super steroids, some really smart guys and an intelligence agency with GOTG we have a talking racoon, a moving tree, intergalactic police and space pirates which is what comics are all about and so far Marvel doesn't know how non-comic book fans will react to these slightly off-beat things. If Guardians goes well Marvel can start experimenting, which leads me to my next point.....
Reason 4: Niche Franchises
There are a LOT of characters in Marvel who have enough material and fan following to make films out of but only the mainstream ones get movies because they're the ones people know. At least that's what we thought until they announced GOTG where we all lost our s***. Like I said in the last point if all goes well they can start experimenting which means comic fans may finally see their favorite characters on screen like The Runaways, Moon Knight or Ka-Zar. There is now hope.
Reason 5: Iron Man
We are well aware that Robert Downey Jr. is beginning to want to leave his fan favorite role as Tony Stark. But how to they let him go? They can't just make him not appear anymore, fans would be outraged and we all know nobody could replace him so how could they do it? Well its simple, follow the comics, in the comics Iron Man became a contributing member of the Guardians and he left Earth for a while. I think this is a satisfactory reason to make him leave it would mean no actor replaced him yet gave a good reason to why he wouldn't be in the films.
Those were my reasons Guardians of the Galaxy is exactly what the MCU needs. Hope you enjoyed it!