I am one of those geeks who is quite snobby about making changes to something that I have liked for years when they make a movie out of it, but I am not as bad as some. Changes made to a character's costume to make it more realistic (Wolverine's yellow spandex) are fine. Organic web shooters on Spider-Man are fine as long as he is a relatable character who becomes a superhero. Flames on Optimus Prime are fine. Optimus Prime's character was the only thing that was well-done in all three Transformers films. My basic rule is that any changes to the character or any indication that the filmmakers are not taking the characters seriously is the problem with alot of these adaptations. Batman's parents were murdered in front of him and that's why he's Batman, which is why any version of Batman where they try to make him light-hearted doesn't work. The Ninja Turtles work both dark and funny ('Secret of the Ooze' was siller than the first film, but took the characters seriously), Batman does not work funny. Star Wars fans were upset that Greedo shot first because Han Solo's story arc was supposed to be that he grew up hard (read the Han Solo trilogy books) and softened when he met Princess Leia. It changes his character if he is a nicer guy at the beginning of the story.
Because of this, I do tend to roll my eyes when they come out with something like 'Brave and the Bold', a cartoon network Batman cartoon that does a great job of teaming Batman up with many DC characters that have not been done before, but...it is a little 'Adam West'. I also tend to roll my eyes at LEGO Batman and LEGO Star Wars and all of these Lego versions of better things. I do tend to forget that, I would not know much about any of the DC superheroes if it were not for the always-corny 'Super Friends' when I was a kid. Yes, 'Justice League' was a better written, more character-driven version (Same with the Ninja Turtles, the original cartoon was corny and then they did a better one in the 2000's) but I know many comic book fans whose first exposure to superheroes was 'Super Friends'. And it was the original 1980's Turtle cartoon that helped me to sniff out the original comics. They were actually the first time that I realized that the superheroes I was watching on TV came from comic books. They may have changed things to appeal to a younger audience and sell toys, but we live in a country that frowns upon comic books. They have ever since the book 'Seduction of the Innocent' blamed comic books for juvinelle crime in the 1950's. Japan's comic book industry has as many comic books as there are TV shows. There, it is not uncommon for old ladies to be seen reading soap opera comic books on the subway, but in this country, anyone over the age of 12 who collects comic books is seen as 'a little weird'. The comic book industry needs the watered-down versions of these properties that appeal to younger kids and sell toys to survive. And then every now and then, you will get 'Batman: the animated series' that appeals to older fans as well. Or they will make a movie like 'Teenage Mutant Ninja Turtles' that goes back to the original subject matter despite the campy changes that the cartoon made.
So, I have concluded that LEGO Batman and LEGO Star Wars is the 'Super Friends' of this generation, a 'gateway drug' into good comic book adaptations just like 'Super Friends' was for me. It is less violent than the real thing (the characters fall apart and come back together) and it gets kids hooked on those characters for when they get older and pushes the genre forward in a way that it is difficult for a comic book snob like me to admit.