"Nobody asks if The Avengers characters are or are not 'fitting' characters. If the cgi of the Avengers are fitting or unfitting. If the jokes of the Avengers movies are fitting or unfitting. "

People absolutely do discuss this, all of the time. Far more so than for The Hobbit. Adaptations are expected to show respect to their source material and fans of said material, and when changes are made people will always discuss those changes whether good or bad. It happens with every franchise out there.

How would you feel if Bilbo suddenly pulled out a laser gun and shot Smaug? It's only fiction, right?

In adaptations like this, especially a prequel, where an entire world and aesthetic and atmosphere has already been laid down and cemented in audience's minds, there are so many expectations to reach by replicating certain looks and themes, so as not to disappoint the expectations of the audience. - If you pay to see a horror you expect to get scared, and would be disappointed otherwise, and this is a similar scenario.

By changing key elements (whether subtly, like 1951's Scrooge or drastically like 1988's Scrooged) you can completely alter the audience's perception and enjoyment of the story.

One story developed over several years - something that is true of the books as it is of the films. And just as with the books, so with the films, the tale grew in the re-telling and there are some differences in style. Inevitably there are also differences in some of the returning characters, who couldn't help growing older in the years that elapsed between the two trilogies.

But - and please note, for me this is an important but - I disassociate myself completely from the sweeping assumptions you make in your post. There is nothing in The Hobbit that takes me out of the filmed universe of Middle Earth - or at least, nothing more than there was in the first trilogy. Both contain the occasional slips into the modern idiomatic language and attitudes which for me is the biggest mood breaker. But I don't agree that they have 'gone too far with certain things' or that the action scenes are 'ridiculous' or that they have overused CGI. I'm still waiting for someone to explain to me how you could make Middle Earth come alive on screen without CGI - funnily enough, no one every does! And as for the supposed 'lack of magic' that above everything makes me think we're discussing different films. I see wonders when I see The Hobbit and would happily watch even if it were in a language I didn't understand. Just last night I was watching Smaug's attack on Laketown and I would defy anyone to better those scenes. So you see, all of those things that you take as fact are nothing more than one subjective opinion. Some share it, some don't. But don't assume that we all agree about these things, it's just that some people don't mind them - because in doing that you're actually misjudging a lot of people. There are problems with The Hobbit that I see and acknowledge, but they're not the ones you're assuming at all. I'd say most of them stem from Peter Jackson and his team having to take over an established project very late in the day, without sufficient time to think how they wanted to shape it. They've had to do an awful lot of thinking on their feet. And given all the other problems they faced, I think that what they achieved is pretty near miraculous.

So I view The Hobbit with pleasure as it is and in time, when the EE is released, will happily view all six as one developing story. There are scenes I absolutely love, scenes I accept as part of the story and a few I don't care for so much in all of them. Ironically, much as I love the first trilogy it also contains the scene I like least in the whole sequence, because it's too far removed from Tolkien's writing or his ideas for me to find any way to rationalise it. But that's just me.