And how that fits into "California Adventure" is another stretch. (Well, come to think of it, parts of the real Hollywood Blvd. are just as ugly...)
How things fit into DCA has been a problem since about June 2001 when they shoved the Electrical Parade over there. Very little truly "fits" the DCA theming structure, and Disney's solution to this stifling problem has been to simply ignore it.
2001: Electrical Parade - it's a "California Classic" (not making this up, they even wrote it in lights on the drum)
2002: a bug's land - there are bugs in California!
2004: Tower of Terror - there's a haunted hotel on this working backlot because Hollywood is crazy, please ignore lack of placemaking and go with us here
2006: Monsters Inc. - movies are made in Hollywood (but not this one, ssshhh be quiet) and this is the Hollywood Pictures Backlot so a dark ride based on this Pixar film can just be plopped here as cheaply as possible
2008: Midway Mania - the toys from Toy Story have a midway game playset and you've inexplicably shrunk down to their size to enjoy it with them on this seaside pier ostensibly set in the early 20th century
2011: Little Mermaid - California has oceans and mermaids live in the ocean therefore this Danish fairy tale book report ride fits into Paradise Pier because aquariums are things that are built next to oceans
2012: Cars Land - there is a desert in California and California people like to drive cars even though this film actually took place in Arizona
2015: Frozen Fun - Frozen is a movie and Hollywood is where movies are supposedly made so it fits into Hollywood Land
2016: Soarin' Around the World - this is my favorite. We went from an attraction as California as it gets to one that has nothing to do with California and the replacement back story from WDI is that the aviators at Grizzly Peak Airfield opened a simulator theatre where you could fly over the most beautiful sites in the world
2017: Guardians - the Collector brought his spaceship-fortress-oil refinery to DCA to show guests his newest acquisitions isn't that neat
The theming gymnastics have been part of DCA's history for 16 stupefying years. The real reason GOTG drives everyone nuts is that it's not Disney, it's not Pixar, it's Marvel. The California theme is already looser than a fanboi meeting Tony Baxter for the first time. Guardians is far from the first square peg in DCA, and it won't be the last.
In 20 years, no one will care that Marvel is in DCA. It'll be part of the fabric, like Lucasfilm projects have been at DL for decades.