I really disliked Narnia. I loved the books, and thought that some of the adult acting was great, (especially JM as Mr Tumulus.) However there was very little to write home about (a common activity during the war) concerning the children, unless you wanted to write home about the poor state of child acting these days. The direction was very stale at times, and the action sequence of the battle left me as cold as the battle in King Arthur of two years ago.
I feel in the way that Superheros are being rolled out in the wake of successes (Spidey, X-men..) then in the wake of successful fantasy films then this is now seen as a goldmine for Hollywood execs. After the massive success of Potter and LotR then we had children's fantasy adaptions on their way, most notable y in recent times with Lemony Snicket and Narnia.
V for Vendetta is another comic that is being adapted for the big screen, but this shows a significant difference in the standard comic book fare. It is dark, amoralistic and ever so slightly preachy. But it provides a new edge. As did Sin City, and Batman Begins, which I will have to disagree with you on. It showed Bruce Wayne for who he is. A man trouble by his past. Unwilling to let go of his current discipline in fear that he will turn into what he hates. HE is perhaps the strongest of the DC heroes because he is essentially only human. He is vulnerable and the closest that we feel we could be if only we had the guts. (and obviously the mansion, the millions and the Michael Caine butler)
I believe that the recent trend in looking for Superheroes does indeed have some basis in real world events. People started to look for heroes, and not just the ones we had been receiving from the eighties in John McClane and Rambo. We wanted ones that could go that extra mile. Ones that we would imagine if they were real not only would they save the world but would pop round for a few cold beers as well in the evening. We have always looked for heroes in films, whether reluctant ( Rick in Casablanca), sacrificial, educated, (Ind anyone?), male or female. Who can;t say they wanted to be a Goonie when they were younger...
Yes it has become a cheap option to cash in on Comic books. They have predefined characters and stories. They come with their own legion of fans and thus interest. However it can often be these fans that turn against the film itself. If you love the comics then you need to be won over by the film, and often the person making the film won't have the same commitment to telling the hero's story that made the original comic so popular.
I think that it has become too easy to adapt a popular comic character, but that doesn't mean I think they should stop. There have been some great adaptations over the past few years and despite having to suffer the terrible, (F4 anyone) we have benefited greatly from this trend.
Must also say I'm looking forward to Joss Wheadon's Wonder woman which you missed off you original list