Movie adaptations - Question the source

I have no idea what ppl's complains are about the recent Dragonball movie.

They say its campy, its lame, plot holes abound and the characters are stupid looking.
Well i say, THATS EXACTLY LIKE THE ORIGINAL MANGA.

Ok seems the movie combines the more aliens and scifi setting in the "popular"(see long winded and draggy) anime Dragonball Z with the setting and plot from the manga Dragonball.

Here's the math.
X= a draggy, plot hole filled show running at 291 episodes(not counting the sequel series and 17 anime movies). Takes at least 5 full episodes(100 minutes) to explain ONE plot point or finish ONE fight. Gaudy, campy, budgetly animated and fun filled power-shooting fest.

Y= A old manga. Read it here and see. Basicall just as campy, over the top, overblown, borderline retarded characters, oh and did i mention theres a lot of pervertic instances?(eg: balls and dicks showing up, ppl craving panties etc). dont believe me read it yourself. Its obviously a parody like Scary movie or Meet the Spartans.

http://www.onemanga.com/Dragon_Ball/


X + Y = Dragonball Evolution movie. A crappy, camp-fest. Over the top, overblown, budget special effects headache inducer with silly characters and cheesy villians.(ok they did not include Goku's balls and the panties obsession. THANK GAWD!!!)

So it brings me to the main point of my post. Which is this.
Why do people complain about a movie adaptation(of whatever) when its the SOURCE MATERIAL thats...........thats like that lor.

Don't get me wrong. There have been movie adaptations that the the fans AND the general public AND reviewers loved.
eg:
Games- Silent Hill, Resident Evil(1 only)
Graphic novels - Dark Knight, Watchmen
Manga- Deathnote(aside from this i can't think of any more that were even passable)
Cartoons - Flintstones

But most of the case, its usually pleases only 1 of the 3(be it th fans OR the public OR the reviewers)

Then you have those movie adaptations that is totally OFF from the original source material. Some have been well liked despite bearing only scant similarities with the original
eg: Blade, Wanted
.



But some have been hated(and i totally agree with the hate)

eg: Initial D, Man Thing




The third category is this
those that are complained about BUT stick close to the source material's essence.


Here are 3 of the most complained about movie adaptations i've seen
example

1) Transformers(Public loved it. Most fans and reviewers hate it. I loved it). Aside from the special effects action which were astounding and the dialogue + acting which was VERY well done, the plot was overly simple, characters almost one dimensional, fights were erratic, and overall the movie is shallow and "brainless".
SO WHATS THE PROBLEM??
The original cartoon(season 1 only. Cos season 2 and 3 were a major improvement) was JUST THAT

. The Epitome(see Godlike) of voice acting and animation(for the 80s) but with simplistic easy to follow stories, pre-set character sterotypes, erratic fights(its not easy to animate robots grappling) and a lack of in depth themes(all themes covered in the 13 episodes of season 1 can be summarised as "Good triumphs over evil". HOW DEEP IS THAT?!?!?!? MY baby brother can tell you that)

2) Doom(fans and reviewers and public all hate it. I liked it)
. The movie was brainless as well. Crappy story, dismal acting, "too much sneaking not enough shooting". Reviewers were quoted saying the movie had "thin character development, cheesy dialogue and lack of story".
Well lets look at Doom 95(the original and sequels) and Doom 3(the remake).
Doom95 HAD NO charcter development, or straight story or dialogue.
Doom 3 has A LOT of sneaking around in the dark, cheesy dialogue and a plot full of holes.
The ONLY change i can see in the movie that is not in the source material is the origin of the monsters being some extra chromosome thing(dont an extra chromosome lead to down syndrome??) and not demons from Hell. Other than that, the movie has everything else from the game.

3) Speed Racer(public hated it. Reviewers give or take. Fans loved it. I loved it).
Just some quotes of reviewers
-implausibility and the lack of identifiable peril in the driving sequences
-colorful and loud but story lacking depth.
-praise for the cinematography and the "playful and busy" musical score
- un-needed chimpanzee tricks, tiresome kid-brother high jinks, unbelievable Ninja martial arts by the whole family and a raft of vicious yet harmless villains
And here are my counter points.

-Its a kids cartoon thats being adapted. No one died in the cartoon, hence the lack of a peril in the races in the movie.
- the cartoon was episodic. Meaning that each episode was a self-contained story aside from the season premiere or ending 3 episode story arc. And like other cartoons of the 70s, the plots were simple yet timeless.
-Yes, the overall look and feel, plus the musical score in the cartoon was definately ahead of its time.
-The chimpanzee and kid brother capers were an "every episode must have" staple. Yes the whole family in the cartoon can kick ass and do. and once again, its a 70s kids cartoon, the villians are vilianous but will most likely tie you up over a pool of sharks and wait for you to escape than just shoot you in the face.
So there you have it. The public disliked the movie FOR BEING TRUE TO THE ORIGINAL in terms of essence and spirit of the show. Yet public, opinion of the speed racer cartoon till this day is rather high.

4) The Spirit
. Problems with the show cited were the inconsistent feel. It was hard boiled detective noir with looney toons zany. It was dark vigilante with camp. BAsically it was everything the original newspaper comic strip was.
Each month brought a different story, and each story was purposely created to have a different feel. One month could be a detective story, the next a comedy, the month after that, a sad tear jerking romance or a dream-like fun filled romp with a campy villian with over the top gadgets.
The movie had all that, within a single movie.
So whats the problem?????


So the question is this.
Why do people complain about movie adaptations' faults when those same "faults"(i dont regard them as faults but rather elements making up the entire essence of the source material) are present in the source material??
Selective memory?? Denial?? Whats your take?