I doubt it would find a publisher today; ... . It shouldn't be banned though. It's a historical document and should be available for anybody to see the origins of Nazism first hand.
My old history teacher said we could 'read a couple of hundred pages for a laugh'; it's so awful that no-one was likely ever to think Hitler wasn't so bad after all having read it. Quite the reverse. I have a vague recollection of reading a few pages.
After copyright expired about 5 years ago, with no publication of it since 1945, a heavily annotated edition was published here for students of history. I remember some of the controversy. There was a fear it might lead some back to the old Reich but I find it difficult to believe that more than a fringe could be that 'dumb'.
The modern concept of life as 'struggle' goes back to one Charles Darwin. Not only Hitler saw life like this, but communism too viewed life as an ongoing struggle between the proletariat and the bourgeoisie. The full title of Darwin's book was
On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. The latter part of the title doesn't seem to be quoted very often these days, and I was very surprised when I saw it!
As for the origins of Nazism, it didn't come out of thin air just after WW1, but was based on ideas and thinking in the Kaiser's Reich, just taken to a greater extreme. This comes out of the literature of the period, which a long time ago I had to read. Something that struck me whilst doing that was just how similar much the thinking of Wilhelmine Germany was to that of Victorian Britain. The French were also very prone to this as well. I think the British were quicker to emerge from this than the continental countries.