My understanding is that Peukert’s The Crisis Years of Classical Modernity has been enormously influential upon the current generation of historians and forced a re-evaluation of how successful Weimar actually was, especially during 1924-29, the “Golden Years”, as well as discrediting the thesis of “a republic without republicans”. But yes, there are probably still many who are far more negative about the Republic’s chances.
I would say that Blackbourn and Eley's work has had a bigger impact, but, sure, the 1980s saw a huge shift in attitudes to modern German history, a shift that has continued, and which was largely generational.* You can probably now count on one hand the number of historians of modern Germany who believe in the
Sonderweg thesis as originally proposed, and not that many who believe in the various modified versions that have sprung up since the early 90s.
*Of course it was not actually the most high profile historiographical debate in Germany in the 1980s, but the less said about that, the better.As for your point about hypotheticals in history, viewing everything as a series of inevitabilities is a very reductionist view, and asking about whether the Republic was doomed is not so much an exercise in alternate history as an attempt to understand its history as those who were there saw it; after all, it is they who make all history.
Ah, no. Inevitability is not a word I used, and I would agree to be wary of it. But 'ought' should be avoided as well. History does not make mistakes. If we assume otherwise then, oddly, we are not so very far removed from the old
Sonderweg position, which was very much rooted in the assumption that German history had taken a deviant turn. What happened
happened and one of the principle duties of the historian is to understand why. This does not mean that we cannot consider what might have been, but it ought not be the primary focus.