The ending of "Sense and sensibility" and my thoughts on Jane Austen

After 4 days, I've finished reading "Sense and sensibility". 
The book has some strengths: smooth writing, many enjoyable passages, insight, understanding of love, description of society, depiction of various types of people, especially repulsive types. 
I believe you're expecting a "but". True. But, there are books that are elevated to a higher level owing to their final chapters and this one happens to be the opposite- the 3 last chapters ruin everything. After going around and tiring the reader, making one wonder whether Marianne will end up with Willoughby or Colonel Brandon or somebody else and Elinor will be with Edward Ferras or Colonel Brandon or an entirely new person, with Willoughby going away and Edward behaving strangely and Colonel Brandon suddenly disappearing and Edward having a secret engagement for 4 years to Lucy Steele and Colonel Brandon growing closer to and more intimate with Elinor though in love with Marianne and Willoughby getting exposed as a libertine and Edward being banished because of the engagement to Lucy and his brother Robert getting the fortune and Willoughby getting married to Miss Grey, the book ends in a most ridiculous way ever- in short, a happy ending where no one, whether good or bad, really suffers. The way Jane Austen puts Lucy Steele with Robert Ferras, and thus, Edward with Elinor, Marianne with Colonel Brandon, is purely grotesque, contradicting and senseless. It makes the novel as a whole become trivial and resemble those Disney films, "Enchanted" for instance, in which the 2 protagonists get happily married and the forsaken ones are randomly thrown together so that nobody is sad in the end. 
It's silly level 1 when Lucy and Robert get married, because nobody understands how they are drawn to each other and attached to each other, and a conceited guy like Robert is, in my opinion, more likely to get married to Miss Morton instead of somebody much below him in position as well as fortune, like Lucy. But let's say that's acceptable. It's silly level 2 when Edward proposes to Elinor, because he is engaged for 4 years to Lucy and willing to sacrifice everything for his love (Lucy) instead of marrying Miss Morton as his mother wishes, then after a very short while he realises that he actually loves Elinor and wishes to marry Elinor. It's also silly because from the beginning to the end, Elinor is a Mary Sue, basically perfect- pretty, deep, thoughtful, well-bred, well-behaved, insightful, sensible, rational but also sensitive, reasonable, calm, trustworthy, considerate, understanding, etc. and in the end loses nothing. But let's also say it's acceptable. It's silly level 3 when Marianne accepts Colonel Brandon, because throughout the novel one can see no real development between these 2 and it's more likely and understandable if Colonel Brandon after a long while shifts his interest from Marianne to Elinor. This ending is thus not only unsatisfying but also, as I said, ridiculous. 
Besides, in the end, when Marianne learns, matures and realises her faults through observing Elinor, she also becomes a sort of Mary Sue. Perfect. 
Am I being too harsh and critical? 
I hope not. Because the whole time I was reading the novel, I found it engrossing and enjoyable and was ready to rid myself of my prejudice against and aversion to Jane Austen, but the ending was shockingly and deeply disappointing that I go back to my former attitude regarding this author.
It's probably true, one can't be a fan of Jane Austen and the Bronte sisters at the same time. 



Update on 3/8/2013: 
Another thing that gets on my nerves, which I forgot to mention, is Willoughby's explanation and justification. It doesn't make him a good guy, but certainly makes him appear better. Which, 1st, gives me the impression that Jane Austen doesn't like to describe true scoundrels- she depicts various vices and foibles in human beings but not very serious negative traits and never truly bad-natured, evil people. Everything in her world is light, toned down. 2nd, it proves that Marianne has never been mistaken, which says that Jane Austen doesn't like her ladies to have false hopes, to be mistaken, so even though it isn't necessary whether or not Willoughby loves Marianne, she wants him to, because otherwise Marianne is simply wrong. Why that is important to Jane Austen is beyond my comprehension. 
That is, I haven't discussed further, because 3rd, how Willoughby persuades Elinor to believe that he doesn't mean what he wrote in the letter, but only copied it from his wife (who read the letter addressed to him, and who forced him to make such a reply) , is another question. 
I wrote in my entry "Why I don't like Jane Austen" that her stories are predictable. "Sense and sensibility" isn't predictable, not because it is better than her other books, but because Jane Austen messes up all the ending, which doesn't make sense and doesn't convince. 
Now, could you please condescend to tell me why this woman has often been counted among the greatest writers? 


Update on 24/8/2014: 
Revised view on the ending: http://thelittlewhiteattic.blogspot.com/2013/11/new-thoughts-on-ending-of-sense-and.html